sqlite/test/notnull2.test

# 2021 February 15
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing optimizations associated with "IS NULL"
# and "IS NOT NULL" operators on columns with NOT NULL constraints.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix notnull2

do_execsql_test 1.0 {
  CREATE TABLE t1(a, b);
  CREATE TABLE t2(c, d NOT NULL);

  WITH x(i) AS (
    SELECT 1 UNION ALL SELECT i+1 FROM x WHERE i<1000
  )
  INSERT INTO t1 SELECT i, i FROM x;
  INSERT INTO t2 SELECT * FROM t1;
}

proc do_vmstep_test {tn sql nstep {res {}}} {
  uplevel [list do_execsql_test $tn.0 $sql $res]

  set vmstep [db status vmstep]
  if {[string range $nstep 0 0]=="+"} {
    set body "if {$vmstep<$nstep} {
      error \"got $vmstep, expected more than [string range $nstep 1 end]\"
    }"
  } else {
    set body "if {$vmstep>$nstep} {
      error \"got $vmstep, expected less than $nstep\"
    }"
  }

  # set name "$tn.vmstep=$vmstep,expect=$nstep"
  set name "$tn.1"
  uplevel [list do_test $name $body {}]
}

do_vmstep_test 1.1.1 {
  SELECT * FROM t1 LEFT JOIN t2 WHERE a=c AND d IS NULL;
} 100 {}
do_vmstep_test 1.1.2 {
  SELECT * FROM t1 LEFT JOIN t2 WHERE a=c AND c IS NULL;
} +1000 {}

do_vmstep_test 1.2.1 {
  SELECT * FROM ( SELECT * FROM t2 ) WHERE d IS NULL
} 100 {}
do_vmstep_test 1.2.2 {
  SELECT * FROM ( SELECT * FROM t2 ) WHERE c IS NULL
} +1000 {}

do_vmstep_test 1.3.1 {
  SELECT * FROM t2 WHERE d IS NULL
} 100 {}
do_vmstep_test 1.3.2 {
  SELECT * FROM t2 WHERE c IS NULL
} +1000 {}

do_vmstep_test 1.4.1 {
  SELECT (d IS NOT NULL) FROM t2 WHERE 0==( d IS NOT NULL )
} 100 {}
do_vmstep_test 1.4.2 {
  SELECT * FROM t2 WHERE 0==( c IS NOT NULL )
} +1000 {}

do_vmstep_test 1.5.1 {
  SELECT count(*) FROM t2 WHERE EXISTS(
    SELECT t2.d IS NULL FROM t1 WHERE t1.a=450
  )
} 10000 {1000}
do_vmstep_test 1.5.2 {
  SELECT count(*) FROM t2 WHERE EXISTS(
    SELECT t2.c IS NULL FROM t1 WHERE t1.a=450
  )
} +100000 {1000}

#-------------------------------------------------------------------------
reset_db
do_execsql_test 2.0 {
  CREATE TABLE T1(a INTEGER PRIMARY KEY, b);
  CREATE TABLE T3(k, v);
}

do_execsql_test 2.1 {
  SELECT * FROM (SELECT a, b FROM t1) LEFT JOIN t3 ON a IS NULL;
}



#-------------------------------------------------------------------------
reset_db
do_execsql_test 3.0 {
  CREATE TABLE t0(c0 PRIMARY KEY);
  INSERT INTO t0(c0) VALUES (0);
}
do_execsql_test 3.1 {
  SELECT * FROM t0 WHERE ((c0 NOT NULL) AND 1) OR (c0 == NULL);
} {0}

# 2021-07-22 https://sqlite.org/forum/forumpost/2078b7edd2
#
reset_db
do_execsql_test 4.0 {
  SELECT *, '/'
  FROM (
      SELECT NULL val FROM (SELECT 1)
      UNION ALL
      SELECT 'missing' FROM (SELECT 1)
  ) a
  LEFT JOIN (SELECT 1)
      ON a.val IS NULL;
} {{} 1 / missing {} /}
do_execsql_test 4.1 {
  CREATE TABLE t1(a INT);
  INSERT INTO t1(a) VALUES(1);
  CREATE TABLE t2(b INT);
  SELECT * FROM (SELECT 3 AS c FROM t1) AS t3 LEFT JOIN t2 ON c IS NULL;
} {3 {}}

finish_test