SQLite

  if( sqlite3AuthCheck(pParse, SQLITE_PRAGMA, zLeft, zRight, zDb) ){
    goto pragma_out;
  }

  /* Send an SQLITE_FCNTL_PRAGMA file-control to the underlying VFS
  ** connection.  If it returns SQLITE_OK, then assume that the VFS
  ** handled the pragma and generate a no-op prepared statement.
  **
  ** IMPLEMENTATION-OF: R-12238-55120 Whenever a PRAGMA statement is parsed,
  ** an SQLITE_FCNTL_PRAGMA file control is sent to the open sqlite3_file
  ** object corresponding to the database file to which the pragma
  ** statement refers.
  **
  ** IMPLEMENTATION-OF: R-29875-31678 The argument to the SQLITE_FCNTL_PRAGMA
  ** file control is an array of pointers to strings (char**) in which the
  ** second element of the array is the name of the pragma and the third
  ** element is the argument to the pragma or NULL if the pragma has no
  ** argument.
  */
  aFcntl[0] = 0;
  aFcntl[1] = zLeft;
  aFcntl[2] = zRight;
  aFcntl[3] = 0;
  db->busyHandler.nBusy = 0;
  rc = sqlite3_file_control(db, zDb, SQLITE_FCNTL_PRAGMA, (void*)aFcntl);

** CAPI3REF: Standard File Control Opcodes
** KEYWORDS: {file control opcodes} {file control opcode}
**
** These integer constants are opcodes for the xFileControl method
** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
** interface.
**
** <ul>
** <li>[[SQLITE_FCNTL_LOCKSTATE]]
** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
** opcode causes the xFileControl method to write the current state of
** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
** into an integer that the pArg argument points to. This capability
** is used during testing and is only available when the SQLITE_TEST
** compile-time option is used.
**
** <li>[[SQLITE_FCNTL_SIZE_HINT]]
** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
** layer a hint of how large the database file will grow to be during the
** current transaction.  This hint is not guaranteed to be accurate but it
** is often close.  The underlying VFS might choose to preallocate database
** file space based on this hint in order to help writes to the database
** file run faster.

** of the char** argument point to a string obtained from [sqlite3_mprintf()]
** or the equivalent and that string will become the result of the pragma or
** the error message if the pragma fails. ^If the
** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 
** [PRAGMA] processing continues.  ^If the [SQLITE_FCNTL_PRAGMA]
** file control returns [SQLITE_OK], then the parser assumes that the
** VFS has handled the PRAGMA itself and the parser generates a no-op
** prepared statement if result string is NULL, or that returns a copy
** of the result string if the string is non-NULL.
** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
** that the VFS encountered an error while handling the [PRAGMA] and the
** compilation of the PRAGMA fails with an error.  ^The [SQLITE_FCNTL_PRAGMA]
** file control occurs at the beginning of pragma statement analysis and so
** it is able to override built-in [PRAGMA] statements.
**
** <li>[[SQLITE_FCNTL_BUSYHANDLER]]

    case SQLITE_FCNTL_SIZE_HINT:
    case SQLITE_FCNTL_CHUNK_SIZE:
      /* no-op these */
      rc = SQLITE_OK;
      break;
    case SQLITE_FCNTL_PRAGMA: {
      char **aFcntl = (char**)pArg;
      /*
      ** EVIDENCE-OF: R-29875-31678 The argument to the SQLITE_FCNTL_PRAGMA
      ** file control is an array of pointers to strings (char**) in which the
      ** second element of the array is the name of the pragma and the third
      ** element is the argument to the pragma or NULL if the pragma has no
      ** argument.
      */
      if( aFcntl[1] && sqlite3_stricmp(aFcntl[1],"multiplex_truncate")==0 ){
        if( aFcntl[2] && aFcntl[2][0] ){
          if( sqlite3_stricmp(aFcntl[2], "on")==0
           || sqlite3_stricmp(aFcntl[2], "1")==0 ){
            pGroup->bTruncate = 1;
          }else
          if( sqlite3_stricmp(aFcntl[2], "off")==0
           || sqlite3_stricmp(aFcntl[2], "0")==0 ){
            pGroup->bTruncate = 0;
          }
        }
        /* EVIDENCE-OF: R-27806-26076 The handler for an SQLITE_FCNTL_PRAGMA
        ** file control can optionally make the first element of the char**
        ** argument point to a string obtained from sqlite3_mprintf() or the
        ** equivalent and that string will become the result of the pragma
        ** or the error message if the pragma fails.
        */
        aFcntl[0] = sqlite3_mprintf(pGroup->bTruncate ? "on" : "off");
        rc = SQLITE_OK;
        break;
      }
      /* If the multiplexor does not handle the pragma, pass it through
      ** into the default case. */
    }

  db eval {
    DELETE FROM t1;
    VACUUM;
  }
  multiplex_file_list mx4test
} {mx4test.db}

# NB:  The PRAGMA multiplex_truncate command is implemented using the
# SQLITE_FCNTL_PRAGMA file-control...
#
# EVIDENCE-OF: R-12238-55120 Whenever a PRAGMA statement is parsed, an
# SQLITE_FCNTL_PRAGMA file control is sent to the open sqlite3_file
# object corresponding to the database file to which the pragma
# statement refers.
#
do_test multiplex4-1.2 {
  db eval {PRAGMA multiplex_truncate}
} {on}
do_test multiplex4-1.3 {
  db eval {PRAGMA multiplex_truncate=off}
} {off}
do_test multiplex4-1.4 {

} {off}
do_test multiplex4-1.8 {
  db eval {PRAGMA multiplex_truncate=1}
} {on}
do_test multiplex4-1.9 {
  db eval {PRAGMA multiplex_truncate=0}
} {off}

# EVIDENCE-OF: R-26188-08449 If the SQLITE_FCNTL_PRAGMA file control
# returns SQLITE_OK, then the parser assumes that the VFS has handled
# the PRAGMA itself and the parser generates a no-op prepared statement
# if result string is NULL, or that returns a copy of the result string
# if the string is non-NULL.
#
do_test multiplex4-1.9-explain {
  db eval {EXPLAIN PRAGMA multiplex_truncate=0;}
} {/String8 \d \d \d off/}

do_test multiplex4-1.10 {
  db eval {
    INSERT INTO t1(x) VALUES(randomblob(250000));
  }
  multiplex_file_list mx4test
} {mx4test.001 mx4test.db}

do_test rdonly-1.1 {
  execsql {
    CREATE TABLE t1(x);
    INSERT INTO t1 VALUES(1);
    SELECT * FROM t1;
  }
} {1}

# EVIDENCE-OF: R-29639-16887 The sqlite3_db_readonly(D,N) interface
# returns 1 if the database N of connection D is read-only, 0 if it is
# read/write, or -1 if N is not the name of a database on connection D.
#
do_test rdonly-1.1.1 {
  sqlite3_db_readonly db main
} {0}

# Changes the write version from 1 to 3.  Verify that the database
# can be read but not written.
#

do_test shrink-1.1 {
  db eval {
    PRAGMA cache_size = 2000;
    CREATE TABLE t1(x,y);
    INSERT INTO t1 VALUES(randomblob(1000000),1);
  }
  set ::baseline sqlite3_memory_used
  # EVIDENCE-OF: R-58814-63508 The sqlite3_db_release_memory(D) interface
  # attempts to free as much heap memory as possible from database
  # connection D.
  sqlite3_db_release_memory db
  expr {$::baseline > [sqlite3_memory_used]+500000}
} {1}
do_test shrink-1.2 {
  set baseline [sqlite3_memory_used]
  db eval {
    UPDATE t1 SET y=y+1;

sqlite3_shutdown
sqlite3_config_pmasz 10
sqlite3_initialize
sqlite3 db test.db


# Configure the sorter to use 3 background threads.
#
# EVIDENCE-OF: R-19249-32353 SQLITE_LIMIT_WORKER_THREADS The maximum
# number of auxiliary worker threads that a single prepared statement
# may start.
#
do_test sort4-init001 {
  db eval {PRAGMA threads=5}
  sqlite3_limit db SQLITE_LIMIT_WORKER_THREADS -1
} {5}
do_test sort4-init002 {
  sqlite3_limit db SQLITE_LIMIT_WORKER_THREADS 3
  db eval {PRAGMA threads}
} {3}


# Minimum number of seconds to run for. If the value is 0, each test
# is run exactly once. Otherwise, tests are repeated until the timeout
# expires.
set SORT4TIMEOUT 0
if {[permutation] == "multithread"} { set SORT4TIMEOUT 300 }

  sqlite3_limit db SQLITE_LIMIT_VARIABLE_NUMBER -1
} $SQLITE_MAX_VARIABLE_NUMBER

#--------------------------------------------------------------------
# Test cases sqllimits1-5.* test that the SQLITE_MAX_LENGTH limit
# is enforced.
#
# EVIDENCE-OF: R-61987-00541 SQLITE_LIMIT_LENGTH The maximum size of any
# string or BLOB or table row, in bytes.
#
db close
sqlite3 db test.db
set LARGESIZE 99999
set SQLITE_LIMIT_LENGTH 100000
sqlite3_limit db SQLITE_LIMIT_LENGTH $SQLITE_LIMIT_LENGTH

do_test sqllimits1-5.1.1 {

  } {1 {string or blob too big}}
}
unset strvalue

#--------------------------------------------------------------------
# Test cases sqllimits1-6.* test that the SQLITE_MAX_SQL_LENGTH limit
# is enforced.
#
# EVIDENCE-OF: R-09808-17554 SQLITE_LIMIT_SQL_LENGTH The maximum length
# of an SQL statement, in bytes.
#
do_test sqllimits1-6.1 {
  sqlite3_limit db SQLITE_LIMIT_SQL_LENGTH 50000
  set sql "SELECT 1 WHERE 1==1"
  set tail " /* A comment to take up space in order to make the string\
                longer without increasing the expression depth */\
                AND   1  ==  1"

  execsql {
    DROP TABLE abc;
  }
} {}

#--------------------------------------------------------------------
# Test cases sqllimits1-8.* test the SQLITE_MAX_COLUMN limit.
#
# EVIDENCE-OF: R-43996-29471 SQLITE_LIMIT_COLUMN The maximum number of
# columns in a table definition or in the result set of a SELECT or the
# maximum number of columns in an index or in an ORDER BY or GROUP BY
# clause.
#
set SQLITE_LIMIT_COLUMN 200
sqlite3_limit db SQLITE_LIMIT_COLUMN $SQLITE_LIMIT_COLUMN
do_test sqllimits1-8.1 {
  # Columns in a table.
  set cols [list]
  for {set i 0} {$i <= $SQLITE_LIMIT_COLUMN} {incr i} {

#--------------------------------------------------------------------
# These tests - sqllimits1-9.* - test that the SQLITE_LIMIT_EXPR_DEPTH
# limit is enforced. The limit refers to the number of terms in 
# the expression.
#
# EVIDENCE-OF: R-12723-08526 SQLITE_LIMIT_EXPR_DEPTH The maximum depth
# of the parse tree on any expression.
#
if {$SQLITE_MAX_EXPR_DEPTH==0} {
  puts -nonewline stderr "WARNING: Compile with -DSQLITE_MAX_EXPR_DEPTH to run "
  puts stderr "tests sqllimits1-9.X"
} else {
  do_test sqllimits1-9.1 {
    set max $::SQLITE_MAX_EXPR_DEPTH
    set expr "(1 [string repeat {AND 1 } $max])"

# in a single VDBE program.
#
# TODO

#--------------------------------------------------------------------
# Test the SQLITE_LIMIT_FUNCTION_ARG limit works. Test case names
# match the pattern "sqllimits1-11.*".
#
# EVIDENCE-OF: R-59001-45278 SQLITE_LIMIT_FUNCTION_ARG The maximum
# number of arguments on a function.
#
for {set max 5} {$max<=$SQLITE_MAX_FUNCTION_ARG} {incr max} {
  do_test sqllimits1-11.$max.1 {
    set vals [list]
    sqlite3_limit db SQLITE_LIMIT_FUNCTION_ARG $::max
    for {set i 0} {$i < $::max} {incr i} {
      lappend vals $i

    catchsql "SELECT myfunc([join $vals ,])"
  } {1 {too many arguments on function myfunc}}
}

#--------------------------------------------------------------------
# Test cases sqllimits1-12.*: Test the SQLITE_MAX_ATTACHED limit.
#
# EVIDENCE-OF: R-41778-26203 SQLITE_LIMIT_ATTACHED The maximum number of
# attached databases.
#
ifcapable attach {
  do_test sqllimits1-12.1 {
    set max $::SQLITE_MAX_ATTACHED
    for {set i 0} {$i < ($max)} {incr i} {
      forcedelete test${i}.db test${i}.db-journal
    }
    for {set i 0} {$i < ($max)} {incr i} {

  } {}
}

#--------------------------------------------------------------------
# Test cases sqllimits1-13.*: Check that the SQLITE_MAX_VARIABLE_NUMBER 
# limit works.
#
# EVIDENCE-OF: R-42363-29104 SQLITE_LIMIT_VARIABLE_NUMBER The maximum
# index number of any parameter in an SQL statement.
#
do_test sqllimits1-13.1 {
  set max $::SQLITE_MAX_VARIABLE_NUMBER
  catchsql "SELECT ?[expr {$max+1}] FROM t1"
} "1 {variable number must be between ?1 and ?$::SQLITE_MAX_VARIABLE_NUMBER}"
do_test sqllimits1-13.2 {
  set max $::SQLITE_MAX_VARIABLE_NUMBER
  set vals [list]

#--------------------------------------------------------------------
# Test cases sqllimits1-15.* verify that the 
# SQLITE_MAX_LIKE_PATTERN_LENGTH limit is enforced. This limit only
# applies to the built-in LIKE operator, supplying an external 
# implementation by overriding the like() scalar function bypasses
# this limitation.
#
# EVIDENCE-OF: R-12940-37052 SQLITE_LIMIT_LIKE_PATTERN_LENGTH The
# maximum length of the pattern argument to the LIKE or GLOB operators.
#
# These tests check that the limit is not incorrectly applied to
# the left-hand-side of the LIKE operator (the string being tested
# against the pattern).
#
set SQLITE_LIMIT_LIKE_PATTERN 1000
sqlite3_limit db SQLITE_LIMIT_LIKE_PATTERN_LENGTH $SQLITE_LIMIT_LIKE_PATTERN
do_test sqllimits1-15.1 {