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<title>Command Line Shell For SQLite</title>
<tcl>hd_keywords {CLI} {Command Line Interface} {command-line shell} \
     {command-line interface} </tcl>
<table_of_contents>

<tcl>hd_fragment intro</tcl>
<h1>Getting Started</h1>

<p>The SQLite project provides a simple command-line program named
<b>sqlite3</b> (or <b>sqlite3.exe</b> on Windows)
that allows the user to manually enter and execute SQL
statements against an SQLite database.  This document provides a brief
introduction on how to use the <b>sqlite3</b> program.

<p>Start the <b>sqlite3</b> program by typing "sqlite3" at the
command prompt, optionally followed 
by the name the file that holds the SQLite database.  If the named
file does not exist, a new database file with the given name will be
created automatically.  If no database file is specified on the
command-line, a temporary database is created, then deleted when 
the "sqlite3" program exits.

<p>On startup, the <b>sqlite3</b> program will show a brief banner
message then prompt you to enter SQL.  Type in SQL statements (terminated
by a semicolon), press "Enter" and the SQL will be executed.</p>

<p>For example, to create a new SQLite database named "ex1" 
with a single table named "tbl1", you might do this:</p>

<tclscript>
proc DisplayCode {body} {
  regsub -all {&} [string trim $body] {\&amp;} body
  regsub -all {>} $body {\&gt;} body
  regsub -all {<} $body {\&lt;} body
  regsub -all {\(\(\(} $body {<b>} body
  regsub -all {\)\)\)} $body {</b>} body
  regsub -all {\[\[\[} $body {<i>} body
  regsub -all {\]\]\]} $body {</i>} body
  #regsub -all { } $body {\&nbsp;} body
  #regsub -all \n $body <br>\n body

  #hd_puts {<blockquote><pre>}
  #hd_puts $body
  #hd_puts {</pre></blockquote>}
  return "<codeblock>$body</codeblock>"
}

DisplayCode {
$ (((sqlite3 ex1)))
SQLite version 3.8.5 2014-05-29 12:36:14
Enter ".help" for usage hints.
sqlite> (((create table tbl1(one varchar(10), two smallint);)))
sqlite> (((insert into tbl1 values('hello!',10);)))
sqlite> (((insert into tbl1 values('goodbye', 20);)))
sqlite> (((select * from tbl1;)))
hello!|10
goodbye|20
sqlite>
}
</tclscript>

<p>Terminate the sqlite3 program by typing your system
End-Of-File character (usually a Control-D).  Use the interrupt
character (usually a Control-C) to stop a long-running SQL statement.</p>

<p>Make sure you type a semicolon at the end of each SQL command!
The sqlite3 program looks for a semicolon to know when your SQL command is
complete.  If you omit the semicolon, sqlite3 will give you a
continuation prompt and wait for you to enter more text to be
added to the current SQL command.  This feature allows you to
enter SQL commands that span multiple lines.  For example:</p>


<tclscript>DisplayCode {
sqlite> (((CREATE TABLE tbl2 ()))
   ...> (((  f1 varchar(30) primary key,)))
   ...> (((  f2 text,)))
   ...> (((  f3 real)))
   ...> ((();)))
sqlite> 
}</tclscript>

<tcl>hd_fragment dblclick</tcl>
<h1>Double-click Startup On Windows</h1>

<p>Windows users can double-click on the <b>sqlite3.exe</b> icon to cause
the command-line shell to pop-up a terminal window running SQLite.  However,
because double-clicking starts the sqlite3.exe without command-line arguments,
no database file will have been specified, so SQLite will use a temporary
database that is deleted when the session exits.
To use a persistent disk file as the database, enter the ".open" command
immediately after the terminal window starts up:

<tclscript>DisplayCode {
SQLite version 3.8.5 2014-05-29 12:36:14
Enter ".help" for usage hints.
Connected to a transient in-memory database.
Use ".open FILENAME" to reopen on a persistent database.
sqlite> (((.open ex1.db)))
sqlite> 
}</tclscript>

<p>The example above causes the database file named "ex1.db" to be opened
and used.  The "ex1.db" file is created if it does not previously exist.
You might want to
use a full pathname to ensure that the file is in the directory that you
think it is in.  Use forward-slashes as the directory separator character.
In other words use "c:/work/ex1.db", not "c:\work\ex1.db".</p>

<p>Alternatively, you can create a new database using the default temporary
storage, then save that database into a disk file using the ".save" command:

<tclscript>DisplayCode {
SQLite version 3.16.0 2016-12-29 19:48:46
Enter ".help" for usage hints.
Connected to a transient in-memory database.
Use ".open FILENAME" to reopen on a persistent database.
sqlite> [[[... many SQL commands omitted ...]]]
sqlite> (((.save ex1.db)))
sqlite> 
}</tclscript>

<p>Be careful when using the ".save" command as it will overwrite any
preexisting database files having the same name without prompting for
confirmation.  As with the ".open" command, you might want to use a
full pathname with forward-slash directory separators to avoid ambiguity.

<tcl>hd_fragment dotcmd {dot-commands}</tcl>
<h1>Special commands to sqlite3 (dot-commands)</h1>

<p>
Most of the time, sqlite3 just reads lines of input and passes them
on to the SQLite library for execution.
But input lines that begin with a dot (".")
are intercepted and interpreted by the sqlite3 program itself.
These "dot commands" are typically used to change the output format
of queries, or to execute certain prepackaged query statements.
</p>

<p>
For a listing of the available dot commands, you can enter ".help"
at any time.  For example:
</p>

<tclscript>DisplayCode {
sqlite> (((.help)))
.archive ...           Manage SQL archives: ".archive --help" for details
.auth ON|OFF           Show authorizer callbacks
.backup ?DB? FILE      Backup DB (default "main") to FILE
.bail on|off           Stop after hitting an error.  Default OFF
.binary on|off         Turn binary output on or off.  Default OFF
.cd DIRECTORY          Change the working directory to DIRECTORY
.changes on|off        Show number of rows changed by SQL
.check GLOB            Fail if output since .testcase does not match
.clone NEWDB           Clone data into NEWDB from the existing database
.databases             List names and files of attached databases
.dbinfo ?DB?           Show status information about the database
.dump ?TABLE? ...      Dump the database in an SQL text format
                         If TABLE specified, only dump tables matching
                         LIKE pattern TABLE.
.echo on|off           Turn command echo on or off
.eqp on|off|full       Enable or disable automatic EXPLAIN QUERY PLAN
.excel                 Display the output of next command in a spreadsheet
.exit                  Exit this program
.expert                EXPERIMENTAL. Suggest indexes for specified queries
.fullschema ?--indent? Show schema and the content of sqlite_stat tables
.headers on|off        Turn display of headers on or off
.help                  Show this message
.import FILE TABLE     Import data from FILE into TABLE
.imposter INDEX TABLE  Create imposter table TABLE on index INDEX
.indexes ?TABLE?       Show names of all indexes
                         If TABLE specified, only show indexes for tables
                         matching LIKE pattern TABLE.
.iotrace FILE          Enable I/O diagnostic logging to FILE
.limit ?LIMIT? ?VAL?   Display or change the value of an SQLITE_LIMIT
.lint OPTIONS          Report potential schema issues. Options:
                         fkey-indexes     Find missing foreign key indexes
.load FILE ?ENTRY?     Load an extension library
.log FILE|off          Turn logging on or off.  FILE can be stderr/stdout
.mode MODE ?TABLE?     Set output mode where MODE is one of:
                         ascii    Columns/rows delimited by 0x1F and 0x1E
                         csv      Comma-separated values
                         column   Left-aligned columns.  (See .width)
                         html     HTML <table> code
                         insert   SQL insert statements for TABLE
                         line     One value per line
                         list     Values delimited by "|"
                         quote    Escape answers as for SQL
                         tabs     Tab-separated values
                         tcl      TCL list elements
.nullvalue STRING      Use STRING in place of NULL values
.once (-e|-x|FILE)     Output for the next SQL command only to FILE
                         or invoke system text editor (-e) or spreadsheet (-x)
                         on the output.
.open ?OPTIONS? ?FILE? Close existing database and reopen FILE
                         The --new option starts with an empty file
.output ?FILE?         Send output to FILE or stdout
.print STRING...       Print literal STRING
.prompt MAIN CONTINUE  Replace the standard prompts
.quit                  Exit this program
.read FILENAME         Execute SQL in FILENAME
.restore ?DB? FILE     Restore content of DB (default "main") from FILE
.save FILE             Write in-memory database into FILE
.scanstats on|off      Turn sqlite3_stmt_scanstatus() metrics on or off
.schema ?PATTERN?      Show the CREATE statements matching PATTERN
                          Add --indent for pretty-printing
.selftest ?--init?     Run tests defined in the SELFTEST table
.separator COL ?ROW?   Change the column separator and optionally the row
                         separator for both the output mode and .import
.session CMD ...       Create or control sessions
.sha3sum ?OPTIONS...?  Compute a SHA3 hash of database content
.shell CMD ARGS...     Run CMD ARGS... in a system shell
.show                  Show the current values for various settings
.stats ?on|off?        Show stats or turn stats on or off
.system CMD ARGS...    Run CMD ARGS... in a system shell
.tables ?TABLE?        List names of tables
                         If TABLE specified, only list tables matching
                         LIKE pattern TABLE.
.testcase NAME         Begin redirecting output to 'testcase-out.txt'
.timeout MS            Try opening locked tables for MS milliseconds
.timer on|off          Turn SQL timer on or off
.trace FILE|off        Output each SQL statement as it is run
.vfsinfo ?AUX?         Information about the top-level VFS
.vfslist               List all available VFSes
.vfsname ?AUX?         Print the name of the VFS stack
.width NUM1 NUM2 ...   Set column widths for "column" mode
                         Negative values right-justify
sqlite> 
}</tclscript>

<tcl>hd_fragment dotrules</tcl>
<h1>Rules for "dot-commands"</h1>

<p>Ordinary SQL statements are free-form, and can be
spread across multiple lines, and can have whitespace and
comments anywhere.  Dot-commands are
more restrictive:

<ul>
<li>A dot-command must begin with the "." at the left margin
    with no preceding whitespace.
<li>The dot-command must be entirely contained on a single input line.
<li>A dot-command cannot occur in the middle of an ordinary SQL
    statement.  In other words, a dot-command cannot occur at a
    continuation prompt.
<li>Dot-commands do not recognize comments.
</ul>

<p>The dot-commands
are interpreted by the sqlite3.exe command-line program, not by
SQLite itself.  So none of the dot-commands will work as an argument
to SQLite interfaces like [sqlite3_prepare()] or [sqlite3_exec()].

<tcl>hd_fragment dotmode</tcl>
<h1>Changing Output Formats</h1>

<p>The sqlite3 program is able to show the results of a query
in eight different formats: "csv", "column", "html", "insert",
"line", "list", "quote", "tabs", and "tcl".
You can use the ".mode" dot command to switch between these output
formats.</p>

<p>The default output mode is "list".  In
list mode, each row of a query result is written on one line of
output and each column within that row is separated by a specific
separator string.  The default separator is a pipe symbol ("|").
List mode is especially useful when you are going to send the output
of a query to another program (such as AWK) for additional processing.</p>

<tclscript>DisplayCode {
sqlite> (((.mode list)))
sqlite> (((select * from tbl1;)))
hello|10
goodbye|20
sqlite>
}</tclscript>

<p>Use the ".separator" dot command to change the separator.
For example, to change the separator to a comma and
a space, you could do this:</p>

<tclscript>DisplayCode {
sqlite> (((.separator ", ")))
sqlite> (((select * from tbl1;)))
hello, 10
goodbye, 20
sqlite>
}</tclscript>

<p>The next ".mode" command will reset the ".separator" back to its default.
So you will need repeat the ".separator" command whenever you change
modes if you want to continue using a non-standard separator.

<p>In "quote" mode, the output is formatted as SQL literals.  Strings are
enclosed in single-quotes and internal single-quotes are escaped by doubling.
Blobs are displayed in hexadecimal blob literal notation (Ex: x'abcd').
Numbers are displayed as ASCII text and NULL values are shown as "NULL".
All columns are separated from each other by a comma (or whatever alternative
character is selected using ".separator").

<tclscript>DisplayCode {
sqlite> (((.mode quote)))
sqlite> (((select * from tbl1;)))
'hello',10
'goodbye',20
sqlite>
}</tclscript>

<p>In "line" mode, each column in a row of the database
is shown on a line by itself.  Each line consists of the column
name, an equal sign and the column data.  Successive records are
separated by a blank line.  Here is an example of line mode
output:</p>

<tclscript>DisplayCode {
sqlite> (((.mode line)))
sqlite> (((select * from tbl1;)))
one = hello
two = 10

one = goodbye
two = 20
sqlite>
}</tclscript>

<p>In column mode, each record is shown on a separate line with the
data aligned in columns.  For example:</p>

<tclscript>DisplayCode {
sqlite> (((.mode column)))
sqlite> (((select * from tbl1;)))
one         two       
----------  ----------
hello       10        
goodbye     20        
sqlite>
}</tclscript>

<p>By default, each column is between 1 and 10 characters wide, depending
on the column header name and the width of the first column of data.
Data that is too wide to fit in a column is truncated.  Use the
".width" dot-command to adjust column widths, like this:</p>

<tclscript>DisplayCode {
sqlite> (((.width 12 6)))
sqlite> (((select * from tbl1;)))
one           two   
------------  ------
hello         10    
goodbye       20    
sqlite>
}</tclscript>

<p>The ".width" command in the example above sets the width of the first
column to 12 and the width of the second column to 6.  All other column
widths were unaltered.  You can gives as many arguments to ".width" as
necessary to specify the widths of as many columns as are in your
query results.</p>

<p>If you specify a column a width of 0, then the column
width is automatically adjusted to be the maximum of three
numbers: 10, the width of the header, and the width of the
first row of data.  This makes the column width self-adjusting.
The default width setting for every column is this 
auto-adjusting 0 value.</p>

<p>Use a negative column width for right-justified columns.</p>

<p>The column labels that appear on the first two lines of output
can be turned on and off using the ".header" dot command.  In the
examples above, the column labels are on.  To turn them off you
could do this:</p>

<tclscript>DisplayCode {
sqlite> (((.header off)))
sqlite> (((select * from tbl1;)))
hello         10    
goodbye       20    
sqlite>
}</tclscript>

<p>Another useful output mode is "insert".  In insert mode, the output
is formatted to look like SQL INSERT statements.  Use insert
mode to generate text that can later be used to input data into a 
different database.</p>

<p>When specifying insert mode, you have to give an extra argument
which is the name of the table to be inserted into.  For example:</p>

<tclscript>DisplayCode {
sqlite> (((.mode insert new_table)))
sqlite> (((select * from tbl1;)))
INSERT INTO "new_table" VALUES('hello',10);
INSERT INTO "new_table" VALUES('goodbye',20);
sqlite>
}</tclscript>


<p>The last output mode is "html".  In this mode, sqlite3 writes
the results of the query as an XHTML table.  The beginning
&lt;TABLE&gt; and the ending &lt;/TABLE&gt; are not written, but
all of the intervening &lt;TR&gt;s, &lt;TH&gt;s, and &lt;TD&gt;s
are.  The html output mode is envisioned as being useful for
CGI.</p>

<tcl>hd_fragment dotoutput</tcl>
<h1>Writing results to a file</h1>

<p>By default, sqlite3 sends query results to standard output.  You
can change this using the ".output" and ".once" commands.  Just put 
the name of an output file as an argument to .output and all subsequent
query results will be written to that file.  Or use the .once command
instead of .output and output will only be redirected for the single next
command before reverting to the console.  Use .output with no arguments to
begin writing to standard output again.  For example:</p>

<tclscript>DisplayCode {
sqlite> (((.mode list)))
sqlite> (((.separator |)))
sqlite> (((.output test_file_1.txt)))
sqlite> (((select * from tbl1;)))
sqlite> (((.exit)))
$ (((cat test_file_1.txt)))
hello|10
goodbye|20
$
}</tclscript>

<p>If the first character of the ".output" or ".once" filename is a pipe
symbol ("|") then the remaining characters are treated as a command and the
output is sent to that command.  This makes it easy to pipe the results
of a query into some other process.  For example, the 
"open -f" command on a Mac opens a text editor to display the content that
it reads from standard input.  So to see the results of a query
in a text editor, one could type:</p>

<tclscript>DisplayCode {
sqlite3> (((.once '|open -f')))
sqlite3> (((SELECT * FROM bigTable;)))
}</tclscript>

<p>If the ".output" or ".once" commands have an argument of "-e" then
output is collected into a temporary file and the system text editor is
invoked on that text file.  Thus, the command ".once -e" achieves the
same result as ".once '|open -f'" but with the benefit of being portable
across all systems.

<p>If the ".output" or ".once" commands have a "-x" argument, that causes
them to accumulate output as Comma-Separated-Values (CSV) in a temporary
file, then invoke the default system utility for viewing CSV files
(usually a spreadsheet program) on the result.  This is a quick way of
sending the result of a query to a spreadsheet for easy viewing:

<tclscript>DisplayCode {
sqlite3> (((.once -x)))
sqlite3> (((SELECT * FROM bigTable;)))
}</tclscript>

<p>The ".excel" command is an alias for ".once -x".  It does exactly the same
thing.

<tcl>hd_fragment fileio {file I/O functions}</tcl>
<h2>File I/O Functions</h2>

<p>The command-line shell adds two [application-defined SQL functions] that
facilitate reading content from a file into a table column, and writing the
content of a column into a file, respectively.

<p>The readfile(X) SQL function reads the entire content of the file named
X and returns that content as a BLOB.  This can be used to load content into
a table.  For example:

<tclscript>DisplayCode {
sqlite> (((CREATE TABLE images(name TEXT, type TEXT, img BLOB);)))
sqlite> (((INSERT INTO images(name,type,img))))
   ...> (((  VALUES('icon','jpeg',readfile('icon.jpg'));)))
}</tclscript>

<p>The writefile(X,Y) SQL function write the blob Y into the file named X
and returns the number of bytes written.  Use this function to extract
the content of a single table column into a file.  For example:

<tclscript>DisplayCode {
sqlite> (((SELECT writefile('icon.jpg',img) FROM images WHERE name='icon';)))
}</tclscript>

<p>Note that the readfile(X) and writefile(X,Y) functions are extension
functions and are not built into the core SQLite library.  These routines
are available as a [loadable extension] in the
[http://www.sqlite.org/src/artifact?ci=trunk&filename=ext/misc/fileio.c|ext/misc/fileio.c]
source file in the [SQLite source code repositories].

<tcl>hd_fragment editfunc {edit() SQL function}</tcl>
<h2>The edit() SQL funtion</h2>

<p>The CLI has another build-in SQL function named edit().  Edit() takes
one or two arguments.  The first argument is a value - usually a large
multi-line string to be edited.  The second argument is the name of a
text editor.  If the second argument is omitted, the VISUAL environment
variable is used.  The edit() function writes its first argument into a
temporary file, invokes the editor on the temporary file, rereads the file
back into memory after the editor is done, then returns the edited text.

<p>The edit() function can be used to make changes to large text
values.  For example:

<tclscript>DisplayCode {
sqlite> (((UPDATE docs SET body=edit(body) WHERE name='report-15';)))
}</tclscript>

<p>In this example, the content of the docs.body field for the entry where
docs.name is "report-15" will be sent to the editor.  After the editor returns,
the result will be written back into the docs.body field.

<p>The default operation of edit() is to invoke a text editor.  But by using
an alternative edit program in the second argument, you can also get it to edit
images or other non-text resources.  For example, if you want to modify a JPEG
image that happens to be stored in a field of a table, you could run:

<tclscript>DisplayCode {
sqlite> (((UPDATE pics SET img=edit(img,'gimp') WHERE id='pic-1542';)))
}</tclscript>

<p>The edit program can also be used as a viewer, by simply ignoring the
return value.  For example, to merely look at the image above, you might run:

<tclscript>DisplayCode {
sqlite> (((SELECT length(edit(img,'gimp')) WHERE id='pic-1542';)))
}</tclscript>


<tcl>hd_fragment schema</tcl>
<h1>Querying the database schema</h1>

<p>The sqlite3 program provides several convenience commands that
are useful for looking at the schema of the database.  There is
nothing that these commands do that cannot be done by some other
means.  These commands are provided purely as a shortcut.</p>

<tcl>hd_fragment dtables {.tables}</tcl>
<p>For example, to see a list of the tables in the database, you
can enter ".tables".</p>


<tclscript>DisplayCode {
sqlite> (((.tables)))
tbl1
tbl2
sqlite>
}</tclscript>


<p>The ".tables" command is similar to setting list mode then
executing the following query:</p>

<tclscript>DisplayCode {
SELECT name FROM sqlite_master 
WHERE type IN ('table','view') AND name NOT LIKE 'sqlite_%'
ORDER BY 1
} </tclscript>

<p>But the ".tables" command does more.  It queries the sqlite_master table
for all [attached] databases, not just the primary database.  And it arranges
its output into neat columns.

<p>The ".indexes" command works in a similar way to list all of
the indexes. If the ".indexes" command is given an argument which is
the name of a table, then it shows just indexes on that table.

<tcl>hd_fragment dschema {.schema}</tcl>
<p>The ".schema" command shows the complete schema for the database,
or for a single table if an optional tablename argument is provided:

<tclscript>DisplayCode {
sqlite> (((.schema)))
create table tbl1(one varchar(10), two smallint)
CREATE TABLE tbl2 (
  f1 varchar(30) primary key,
  f2 text,
  f3 real
)
sqlite> (((.schema tbl2)))
CREATE TABLE tbl2 (
  f1 varchar(30) primary key,
  f2 text,
  f3 real
)
sqlite>
}</tclscript>


<p>The ".schema" command is roughly the same as setting
list mode, then entering the following query:</p>

<tclscript>DisplayCode {
SELECT sql FROM sqlite_master
ORDER BY tbl_name, type DESC, name
} </tclscript>

<p>As with ".tables", the ".schema" command shows the schema for
all [attached] databases.  If you only want to see the schema for
a single database (perhaps "main") then you can add an argument
to ".schema" to restrict its output:

<tclscript>DisplayCode {
sqlite> (((.schema main.*)))
}</tclscript>

<p>The ".schema" command can be augmented with the "--indent" option,
in which case it tries to reformat the various CREATE statements of
the schema so that they are more easily readable by humans.

<p>The ".databases" command shows a list of all databases open in
the current connection.  There will always be at least 2.  The first
one is "main", the original database opened.  The second is "temp",
the database used for temporary tables. There may be additional 
databases listed for databases attached using the ATTACH statement.
The first output column is the name the database is attached with, 
and the second column is the filename of the external file.</p>

<tclscript>DisplayCode {
sqlite> (((.databases)))
}</tclscript>

<tcl>hd_fragment fullschema {the .fullschema dot-command} {.fullschema}</tcl>
<p>The ".fullschema" dot-command works like the ".schema" command in
that it displays the entire database schema.  But ".fullschema" also
includes dumps of the statistics tables "sqlite_stat1", "sqlite_stat3",
and "sqlite_stat4", if they exist.  The ".fullschema" command normally
provides all of the information needed to exactly recreate a query
plan for a specific query.  When reporting suspected problems with
the SQLite query planner to the SQLite development team, developers
are requested to provide the complete ".fullschema" output as part
of the trouble report.  Note that the sqlite_stat3 and sqlite_stat4
tables contain samples of index entries and so might contain sensitive
data, so do not send the ".fullschema" output of a proprietary database
over a public channel.</p>

<tcl>hd_fragment csv {CSV import} {.import}</tcl>
<h1>CSV Import</h1>

<p>Use the ".import" command to import CSV (comma separated value) data into
an SQLite table.  The ".import" command takes two arguments which are the
name of the disk file from which CSV data is to be read and the name of the
SQLite table into which the CSV data is to be inserted.

<p>Note that it is important to set the "mode" to "csv" before running the
 ".import" command.  This is necessary to prevent the command-line shell
from trying to interpret the input file text as some other format.

<tclscript>DisplayCode {
sqlite> (((.mode csv)))
sqlite> (((.import C:/work/somedata.csv tab1)))
}</tclscript>

<p>There are two cases to consider:  (1) Table "tab1" does not previously
exist and (2) table "tab1" does already exist.

<p>In the first case, when the table does not previously exist, the table is
automatically created and the content of the first row of the input CSV
file is used to determine the name of all the columns in the table.  In
other words, if the table does not previously exist, the first row of the
CSV file is interpreted to be column names and the actual data starts on
the second row of the CSV file.

<p>For the second case, when the table already exists, every row of the
CSV file, including the first row, is assumed to be actual content.  If
the CSV file contains an initial row of column labels, that row will be
read as data and inserted into the table.  To avoid this, make sure that
table does not previously exist.

<tcl>hd_fragment csvout {CSV export}</tcl>
<h1>CSV Export</h1>

<p>To export an SQLite table (or part of a table) as CSV, simply set
the "mode" to "csv" and then run a query to extract the desired rows
of the table.

<tclscript>DisplayCode {
sqlite> (((.header on)))
sqlite> (((.mode csv)))
sqlite> (((.once c:/work/dataout.csv)))
sqlite> (((SELECT * FROM tab1;)))
sqlite> (((.system c:/work/dataout.csv)))
}</tclscript>

<p>In the example above, the ".header on" line causes column labels to
be printed as the first row of output.  This means that the first row of
the resulting CSV file will contain column labels.  If column labels are
not desired, set ".header off" instead. (The ".header off" setting is
the default and can be omitted if the headers have not been previously
turned on.)

<p>The line ".once <i>FILENAME</i>" causes all query output to go into
the named file instead of being printed on the console.  In the example
above, that line causes the CSV content to be written into a file named
"C:/work/dataout.csv".

<p>The final line of the example (the ".system c:/work/dataout.csv")
has the same effect as double-clicking on the c:/work/dataout.csv file
in windows.  This will typically bring up a spreadsheet program to display
the CSV file.

<p>That command only works as written on Windows.  
The equivalent line on a Mac would be:

<tclscript>DisplayCode {
sqlite> (((.system open dataout.csv)))
}</tclscript>

<p>On Linux and other unix systems you will need to enter something like:


<tclscript>DisplayCode {
sqlite> (((.system xdg-open dataout.csv)))
}</tclscript>

<tcl>hd_fragment exexcel* {export to excel}</tcl>
<h2> Export to Excel </h2>

<p>To simplify export to a spreadsheet, the CLI provides the
".excel" command which captures the output of a single query and sends
that output to the default spreadsheet program on the host computer.
Use it like this:

<tclscript>DisplayCode {
sqlite> (((.excel)))
sqlite> (((SELECT * FROM tab;)))
}</tclscript>

<p>
The command above writes the output of the query as CSV into a temporary
file, invokes the default handler for CSV files (usually the preferred
spreadsheet program such as Excel or LibreOffice), then deletes the
temporary file.  This is essentially a short-hand method of doing
the sequence of ".csv", ".once", and ".system" commands described above.

<p>
The ".excel" command is really an alias for ".once -x".  The -x option
to .once causes it to writes results as CSV into a temporary file that
is named with a ".csv" suffix, then invoke the systems default handler
for CSV files.

<p>
There is also a ".once -e" command which works similarly, except that
it names the temporary file with a ".txt" suffix so that the default
text editor for the system will be invoked, instead of the default
spreadsheet.

<tcl>hd_fragment dump {.dump}</tcl>
<h1>Converting An Entire Database To An ASCII Text File</h1>

<p>Use the ".dump" command to convert the entire contents of a
database into a single ASCII text file.  This file can be converted
back into a database by piping it back into <b>sqlite3</b>.</p>

<p>A good way to make an archival copy of a database is this:</p>


<tclscript>DisplayCode {
$ (((sqlite3 ex1 .dump | gzip -c >ex1.dump.gz)))
}</tclscript>


<p>This generates a file named <b>ex1.dump.gz</b> that contains everything
you need to reconstruct the database at a later time, or on another
machine.  To reconstruct the database, just type:</p>


<tclscript>DisplayCode {
$ (((zcat ex1.dump.gz | sqlite3 ex2)))
}</tclscript>


<p>The text format is pure SQL so you
can also use the .dump command to export an SQLite database
into other popular SQL database engines.  Like this:</p>


<tclscript>DisplayCode {
$ (((createdb ex2)))
$ (((sqlite3 ex1 .dump | psql ex2)))
}</tclscript>

<tcl>hd_fragment dotload</tcl>
<h1>Loading Extensions</h1>

<p>You can add new custom [application-defined SQL functions],
[collating sequences], [virtual tables], and [VFSes] to the command-line
shell at run-time using the ".load" command.  First, convert the
extension in to a DLL or shared library (as described in the
[Run-Time Loadable Extensions] document) then type:

<tclscript>DisplayCode {
sqlite> .load /path/to/my_extension
}</tclscript>

<p>Note that SQLite automatically adds the appropriate extension suffix
(".dll" on windows, ".dylib" on Mac, ".so" on most other unixes) to the
extension filename.  It is generally a good idea to specify the full
pathname of the extension.

<p>SQLite computes the entry point for the extension based on the extension
filename.  To override this choice, simply add the name of the extension
as a second argument to the ".load" command.

<p>Source code for several useful extensions can be found in the
<a href="http://www.sqlite.org/src/tree?name=ext/misc&ci=trunk">ext/misc</a>
subdirectory of the SQLite source tree.  You can use these extensions
as-is, or as a basis for creating your own custom extensions to address
your own particular needs.

<tcl>hd_fragment sha3sum {.sha3sum dot-command}</tcl>
<h1>Cryptographic Hashes Of Database Content</h1>

<p>The ".sha3sum" dot-command computes a
[https://en.wikipedia.org/wiki/SHA-3|SHA3] hash of the <em>content</em>
of the database.  To be clear, the hash is computed over the database content,
not its representation on disk.  This means, for example, that a [VACUUM]
or similar data-preserving transformation does not change the hash.

<p>The ".sha3sum" command supports options "--sha3-224", "--sha3-256", 
"--sha3-384", and "--sha3-512" to define which variety of SHA3 to use
for the hash.  The default is SHA3-256.

<p>The database schema (in the [sqlite_master] table) is not normally
included in the hash, but can be added by the "--schema" option.

<p>The ".sha3sum" command takes a single optional argument which is a
[LIKE] pattern.  If this option is present, only tables whose names match
the [LIKE] pattern will be hashed.

<p>The ".sha3sum" command is implemented with the help of the
[https://www.sqlite.org/src/file/ext/misc/shathree.c|extension function "sha3_query()"]
that is included with the command-line shell.

<tcl>hd_fragment selftest {.selftest dot-command}</tcl>
<h1>Database Content Self-Tests</h1>

<p>The ".selftest" command attempts to verify that a database is
intact and is not corrupt.  
The .selftest command looks for a table in schema named "selftest"
and defined as follows:

<tclscript>DisplayCode {
CREATE TABLE selftest(
  tno INTEGER PRIMARY KEY,  -- Test number
  op TEXT,                  -- 'run' or 'memo'
  cmd TEXT,                 -- SQL command to run, or text of "memo"
  ans TEXT                  -- Expected result of the SQL command
);
}</tclscript>

<p>The .selftest command reads the rows of the selftest table in
selftest.tno order.
For each 'memo' row, it writes the text in 'cmd' to the output.  For
each 'run' row, it runs the 'cmd' text as SQL and compares the result
to the value in 'ans', and shows an error message if the results differ.

<p>If there is no selftest table, the ".selftest" command runs
[PRAGMA integrity_check].

<p>The ".selftest --init" command creates the selftest table if it
does not already exists, then appends entries that check the SHA3
hash of the content of all tables.  Subsequent runs of ".selftest"
will verify that the database has not been changed in any way.  To
generates tests to verify that a subset of the tables are unchanged,
simply run ".selftest --init" then [DELETE] the selftest rows that
refer to tables that are not constant.  

<tcl>hd_fragment sqlar {SQL Archive} {.archive command}</tcl>
<h1>SQLAR Archive Support</h1>

<p>The ".archive" dot-command (often abbreviated as ".ar")
provides built-in support for the 
[https://sqlite.org/sqlar|SQLite ARchive format]. The interface is similar to
that of the "tar" command on unix systems. Each invocation of the ".ar"
command must specify a single command option. The following commands
are available:

<table striped=1>
  <tr><th style="width:15ex">Option<th style="width:17ex">Long&nbsp;Option<th>Purpose
  <tr><td>-c<td>--create<td>Create a new archive containing specified files.
  <tr><td>-x<td>--extract<td>Extract specified files from archive.
  <tr><td>-t<td>--list<td>List the files in the archive.
  <tr><td>-u<td>--update<td>Add files to existing archive.
</table>

<p>As well as the command option, each invocation of ".ar" may specify
one or more modifier options. Some modifier options require an argument,
some do not. The following modifier options are available:

<table striped=1>
  <tr><th style="width:15ex">Option<th style="width:17ex">Long&nbsp;Option<th>Purpose
  <tr><td>-v<td>--verbose<td>List each file as it is processed.
  <tr><td>-f FILE<td>--file FILE<td>If specified, use file FILE as the
  archive. Otherwise, assume that the current "main" database is the 
  archive to be operated on.
  <tr><td>-a FILE<td>--append FILE<td>Like --file, use file FILE as the
  archive, but open the file using the 
  [https://sqlite.org/src/file/ext/misc/appendvfs.c|apndvfs VFS] so that
  the archive will be appended to the end of FILE if FILE already exists.
  <tr><td>-C DIR<td>--directory DIR<td>If specified, interpret all relative
  paths as relative to DIR, instead of the current working directory.
  <tr><td>-n<td>--dryrun<td>Show the SQL that would be run to carry out the
                       archive operation, but do not actually change anything.
  <tr><td>--<td>--<td>All subsequent command line words are command arguments,
  not options.
</table>

<p>
Long and short style options may be mixed. For example, the following are
equivalent:

<codeblock>
  <i>-- Two ways to create a new archive named "new_archive.db" containing</i>
  <i>-- files "file1", "file2" and "file3".</i>
  .ar -c --file new_archive.db file1 file2 file3
  .ar -f new_archive.db --create file1 file2 file3
</codeblock>

<p>Alternatively, the first argument following to ".ar" may be the concatenation
of the short form of all required options (without the "-" characters). In 
this case arguments for options requiring them are read from the command line
next, and any remaining words are considered command arguments. For example:

<codeblock>
  <i>-- Create a new archive "new_archive.db" containing files "file1" and</i>
  <i>-- "file2" from directory "dir1".</i>
  .ar cCf dir1 new_archive.db file1 file2 file3
</codeblock>

<h2> SQLAR Create Command </h2>

<p>Create a new archive, overwriting any existing archive (either in the current
"main" db or in the file specified by a --file option). Each argument following
the options is a file to add to the archive. Directories are imported
recursively. See above for examples.

<h2> SQLAR Extract Command </h2>

<p>Extract files from the archive (either to the current working directory or
to the directory specified by a --directory option). If there are no arguments
following the options all files are extracted from the archive. Or, if there
are arguments, they are the names of files to extract from the archive. Any
specified directories are extracted recursively. It is an error if any
specified files are not part of the archive.

<codeblock>
  <i>-- Extract all files from the archive in the current "main" db to the</i>
  <i>-- current working directory. List files as they are extracted. </i>
  .ar --extract --verbose

  <i>-- Extract file "file1" from archive "ar.db" to directory "dir1".</i>
  .ar fCx ar.db dir1 file1
</codeblock>

<h2> SQLAR List Command </h2>

<p>List the contents of the archive. If no arguments are specified, then all
files are listed. Otherwise, only those specified as arguments are. Currently,
the --verbose option does not change the behaviour of this command. That may
change in the future.

<codeblock>
  <i>-- List contents of archive in current "main" db.</i>.
  .ar --list
</codeblock>

<h2> SQLAR Update Command </h2>

<p> This command works the same way as the --create command, except that 
it does not delete the current archive before commencing. New versions of
files silently replace existing files with the same names, but otherwise
the initial contents of the archive (if any) remain intact.


<h2> Operations On ZIP Archives </h2>

<p>If FILE is a ZIP archive rather than an SQLAR, the ".archive" command still
works, except that only --extract and --list operations are supported.
ZIP archives are currently read-only to SQLite.  (This limitation may be
relaxed in a future release.)

<h2> SQL Used To Implement SQLAR Operations </h2>

<p>The various SQLAR Archive commands are implemented using SQL statements.
Application developers can easily add SQLAR Archive reading and writing
support to their own projects by running the appropriate SQL.

<p>To see what SQL statements are used to implement an SQLAR Archive
operation, add the --dryrun or -n option.  This causes the SQL to be
displayed but inhibits the execution of the SQL.

<p>The SQL statements used to implement SQLAR operations make use of
various [loadable extensions].  These extensions are all available in
the [https://sqlite.org/src|SQLite source tree] in the
[https://sqlite.org/src/file/ext/misc|ext/misc/ subfolder].
The extensions needed for full SQLAR support include:

<ol>
<li><p>
[https://sqlite.org/src/file/ext/misc/fileio.c|fileio.c] &mdash;
This extension adds SQL functions readfile() and writefile() for
reading and writing content from files on disk.  The fileio.c
extension also includes fsdir() table-valued function for listing
the contents of a directory and the lsname() function for converting
numeric st_mode integers from the stat() system call into human-readable
strings after the fashion of the "ls -l" command.

<li><p>
[https://sqlite.org/src/file/ext/misc/sqlar.c|sqlar.c] &mdash;
This extension adds the sqlar_compress() and sqlar_uncompress()
functions that are needed to compress and uncompress file content
as it is insert and extracted from an SQLAR.

<li><p>
[zipfile|zipfile.c] &mdash;
This extension implements the "zipfile(FILE)" table-valued function
which is used to read ZIP archives.  This extension is only needed
when reading ZIP archives instead of SQLAR archives.

<li><p>
[https://sqlite.org/src/file/ext/misc/appendvfs.c|appendvfs.c] &mdash;
This extension implements a new [VFS] that allows an SQLite database
to be appended to some other file, such as an executable.  This
extension is only needed if the --append option to the .archive
command is used.
</ol>

<tcl>hd_fragment expert {.expert command}</tcl>
<h1>Index Recommendations (SQLite Expert)</h1>

<p><b>Note: This command is experimental. It may be removed or the 
interface modified in incompatible ways at some point in the future.

<p>For most non-trivial SQL databases, the key to performance is creating
the right SQL indexes. In this context "the right SQL indexes" means those
that cause the queries that an application needs to optimize run fast. The
".expert" command can assist with this by proposing indexes that might
assist with specific queries, were they present in the database.

<p>The ".expert" command is issued first, followed by the SQL query 
on a separate line. For example, consider the following session:

<codeblock>
sqlite&gt; CREATE TABLE x1(a, b, c);                  <i>-- Create table in database </i>
sqlite&gt; .expert
sqlite&gt; SELECT * FROM x1 WHERE a=? AND b&gt;?;        <i>-- Analyze this SELECT </i>
CREATE INDEX x1_idx_000123a7 ON x1(a, b);

0|0|0|SEARCH TABLE x1 USING INDEX x1_idx_000123a7 (a=? AND b&gt;?)

sqlite&gt; CREATE INDEX x1ab ON x1(a, b);             <i>-- Create the recommended index </i>
sqlite&gt; .expert
sqlite&gt; SELECT * FROM x1 WHERE a=? AND b&gt;?;        <i>-- Re-analyze the same SELECT </i>
(no new indexes)

0|0|0|SEARCH TABLE x1 USING INDEX x1ab (a=? AND b&gt;?)
</codeblock>

<p>In the above, the user creates the database schema (a single table - "x1"),
and then uses the ".expert" command to analyze a query, in this case 
"SELECT * FROM x1 WHERE a=? AND b&gt;?". The shell tool recommends that the
user create a new index (index "x1_idx_000123a7") and outputs the plan
that the query would use in [EXPLAIN QUERY PLAN] format. The user then creates
an index with an equivalent schema and runs the analysis on the same query
again. This time the shell tool does not recommend any new indexes, and 
outputs the plan that SQLite will use for the query given the existing 
indexes.

<p>The ".expert" command accepts the following options:

<table striped=1>
<tr><th> Option <th> Purpose
<tr><td> --verbose 
    <td> If present, output a more verbose report for each query analyzed.
<tr><td> --sample&nbsp;PERCENT 
    <td> By default, the ".expert" command recommends indexes based on the
         query and database schema alone. This is similar to the way the
         [SQLite query planner] selects indexes for queries if the user has not
         run the [ANALYZE] command on the database to generate data
         distribution statistics. 
         <div style="margin-top:1ex">
         If this option is passed a non-zero argument, the ".expert" command
         generates similar data distribution statistics for all indexes
         considered based on PERCENT percent of the rows currently stored in
         each database table. For databases with unusual data distributions,
         this may lead to better index recommendations, particularly if the
         application intends to run ANALYZE.
         <div style="margin-top:1ex">
         For small databases and modern CPUs, there is usually no reason not
         to pass "--sample 100". However, gathering data distribution
         statistics can be expensive for large database tables. If the
         operation is too slow, try passing a smaller value for the --sample
         option.
</table>

<p>Th functionality described in this section may be integrated into other
applications or tools using the 
<a href="http://www.sqlite.org/src/dir?ci=trunk&name=ext/expert">
SQLite expert extension</a> code.

<tcl>hd_fragment dotother</tcl>
<h1>Other Dot Commands</h1>

<p>There are many other dot-commands available in the command-line
shell.  See the ".help" command for a complete list for any particular
version and build of SQLite.

<tcl>hd_fragment insh</tcl>
<h1>Using sqlite3 in a shell script</h1>

<p>
One way to use sqlite3 in a shell script is to use "echo" or
"cat" to generate a sequence of commands in a file, then invoke sqlite3
while redirecting input from the generated command file.  This
works fine and is appropriate in many circumstances.  But as
an added convenience, sqlite3 allows a single SQL command to be
entered on the command line as a second argument after the
database name.  When the sqlite3 program is launched with two
arguments, the second argument is passed to the SQLite library
for processing, the query results are printed on standard output
in list mode, and the program exits.  This mechanism is designed
to make sqlite3 easy to use in conjunction with programs like
"awk".  For example:</p>

<tclscript>DisplayCode {
$ (((sqlite3 ex1 'select * from tbl1' |)))
> ((( awk '{printf "<tr><td>%s<td>%s\n",$1,$2 }')))
<tr><td>hello<td>10
<tr><td>goodbye<td>20
$
}</tclscript>

<tcl>hd_fragment endsh</tcl>
<h1>Ending shell commands</h1>

<p>
SQLite commands are normally terminated by a semicolon.  In the shell 
you can also use the word "GO" (case-insensitive) or a slash character 
"/" on a line by itself to end a command.  These are used by SQL Server 
and Oracle, respectively.  These won't work in <b>sqlite3_exec()</b>, 
because the shell translates these into a semicolon before passing them 
to that function.</p>


<tcl>hd_fragment compiling</tcl>
<h1>Compiling the sqlite3 program from sources</h1>

<p>
To compile the command-line shell on unix systems and on Windows with MinGW,
the usual configure-make command works:

<codeblock>
sh configure; make
</codeblock>

<p>
The configure-make works whether your are building from the canonical sources
from the source tree, or from a amalgamated bundle.  There are few
dependencies.  When building from canonical sources, a working 
[https://www.tcl.tk/man/tcl8.3/UserCmd/tclsh.htm|tclsh] is required.
If using an amalgamation bundle, all the preprocessing work normally 
done by tclsh will have already been carried out and only normal build
tools are required.

<p>
A working [https://zlib.net|zlib compression library] is
needed in order for the [.archive command] to operate.

<p>
On Windows with MSVC, use nmake with the Makefile.msc:

<codeblock>
nmake /f Makefile.msc
</codeblock>

<p>
For correct operation of the [.archive command], make a copy of the
[https://zlib.net|zlib source code] into the compat/zlib subdirectory 
of the source tree and compile this way:

<codeblock>
nmake /f Makefile.msc USE_ZLIB=1
</codeblock>

<h2> Do-It-Yourself Builds </h2>

<p>
The source code to the sqlite3 command line interface is in a single
file named "shell.c".  The shell.c source file is generated from other
sources, but most of the code for shell.c can be found in
[https://sqlite.org/src/file/src/shell.c.in|src/shell.c.in].
(Regenerate shell.c by typing "make shell.c" from the canonical source tree.)
[how to compile|Compile] the shell.c file (together
with the [amalgamation | sqlite3 library source code]) to generate
the executable.  For example:</p>

<tclscript>DisplayCode {
gcc -o sqlite3 shell.c sqlite3.c -ldl -lpthread -lz -lm
} </tclscript>

<p>
The following additional compile-time options are recommended in order to
provide a full-featured command-line shell:

<ul>
<li> [-DSQLITE_THREADSAFE=0]
<li> [-DSQLITE_ENABLE_EXPLAIN_COMMENTS]
<li> [-DSQLITE_USE_ZLIB]
<li> [-DSQLITE_INTROSPECTION_PRAGMAS]
<li> [-DSQLITE_ENABLE_UNKNOWN_SQL_FUNCTION]
<li> [-DSQLITE_ENABLE_STMTVTAB]
<li> [-DSQLITE_ENABLE_DBPAGE_VTAB]
<li> [-DSQLITE_ENABLE_DBSTAT_VTAB]
<li> [-DSQLITE_ENABLE_OFFSET_SQL_FUNC]
<li> [-DSQLITE_ENABLE_JSON1]
<li> [-DSQLITE_ENABLE_RTREE]
<li> [-DSQLITE_ENABLE_FTS4]
<li> [-DSQLITE_ENABLE_FTS5]
</ul>