Documentation Source Text

     or
        {line ON expr}
        {line USING ( {loop /column-name ,} )}
        nil
  }
  ordering-term {
      line expr {opt COLLATE /collation-name} {or nil ASC DESC} 
                {or nil {line NULLS FIRST} {line NULLS LAST}}
  }
  compound-operator {
     or UNION {line UNION ALL} INTERSECT EXCEPT
  }
  update-stmt {
     rightstack
        {line {opt with-clause} UPDATE {or {} {line OR ROLLBACK}

  set aChng($nChng) [list $date $desc $options]
  set xrefChng($date) $nChng
  incr nChng
}

chng {2019-10-00 (3.30.0)} {
<li> Add support for the [FILTER clause on aggregate functions].
<li> Add support for the [NULLS FIRST] and [NULLS LAST] syntax in [ORDER BY] clauses.
<li> The [index_info] and [index_xinfo] pragmas are enhanced to provide
     information about the on-disk representation of [WITHOUT ROWID]
     tables.
<li> Add the [sqlite3_drop_modules()] interface, allowing applications
     to disable automatically loaded virtual tables that they do not
     need.
<li> Improvements to the [.recover dot-command] in the [CLI] so that
     it recovers more content from corrupt database files.
<li> Enhance the [RBU] extension to support [indexes on expressions].
<li> Change the schema parser so that it will error out if any of
     the type, name, and tbl_name columns of the [sqlite_master table]
     have been corrupted and the database connection is not in
     [writable_schema] mode.

<tcl>hd_fragment comparisons {comparison expressions}</tcl>
<h1>Comparison Expressions</h1>

<p>SQLite version 3 has the usual set of SQL comparison operators
including "=", "==", "&lt;", "&lt;=", "&gt;", "&gt;=", "!=", "<>",
"IN", "NOT IN", "BETWEEN", "IS", and "IS NOT", .

<tcl>hd_fragment sortorder {sort order}</tcl>
<h2>Sort Order</h2>

<p>The results of a comparison depend on the storage classes of the
operands, according to the following rules:</p>
<ul>
  <li><p>^A value with storage class NULL is considered less than any
  other value (including another value with storage class NULL).</p>

and later are able to understand
the descending index format. For compatibility, version of SQLite between 3.3.0
and 3.7.9 use the legacy schema format by default.  The newer schema format is
used by default in version 3.7.10 ([dateof:3.7.10]) and later.
^The [legacy_file_format pragma] can be used to change set the specific
behavior for any version of SQLite.</p>

<p>The NULLS FIRST and NULLS LAST predicates are not supported
for indexes.  For [sort order|sorting purposes], SQLite considers NULL values 
to be smaller than all other values.  Hences NULL values always appear at
the beginning of an ASC index and at the end of a DESC index.</p>

<tcl>hd_fragment collidx {COLLATE}</tcl>
<p>^The COLLATE clause optionally following each column name
or expression defines a
collating sequence used for text entries in that column.
^The default collating
sequence is the collating sequence defined for that column in the
[CREATE TABLE] statement.  ^Or if no collating sequence is otherwise defined,

evaluating the left-most expression in the ORDER BY list, then ties are broken
by evaluating the second left-most expression and so on. The order in which
two rows for which all ORDER BY expressions evaluate to equal values are
returned is undefined. ^Each ORDER BY expression may be optionally followed
by one of the keywords ASC (smaller values are returned first) or DESC (larger
values are returned first). ^If neither ASC or DESC are specified, rows
are sorted in ascending (smaller values first) order by default.

<tcl>hd_fragment nullslast {NULLS FIRST} {NULLS LAST}</tcl>
<p>SQLite considers NULL values to be smaller than any other values
for sorting purposes.  Hence, NULLs naturally appear at the beginning
of an ASC order-by and at the end of a DESC order-by.  This can be changed
using the "ASC NULLS LAST" or "DESC NULLS FIRST" syntax.

<p>Each ORDER BY expression is processed as follows:</p>

<ol>
<li><p>^If the ORDER BY expression is a constant integer K then the
expression is considered an alias for the K-th column of the result set
(columns are numbered from left to right starting with 1).