where4.test

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# 2006 October 27
#
# 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 the use of indices in WHERE clauses.
# This file was created when support for optimizing IS NULL phrases
# was added.  And so the principle purpose of this file is to test
# that IS NULL phrases are correctly optimized.  But you can never
# have too many tests, so some other tests are thrown in as well.
#
# $Id: where4.test,v 1.2 2007/01/25 16:56:08 drh Exp $

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

# Build some test data
#
do_test where4-1.0 {
  execsql {
    CREATE TABLE t1(w, x, y);
    CREATE INDEX i1wxy ON t1(w,x,y);
    INSERT INTO t1 VALUES(1,2,3);
    INSERT INTO t1 VALUES(1,NULL,3);
    INSERT INTO t1 VALUES('a','b','c');
    INSERT INTO t1 VALUES('a',NULL,'c');
    INSERT INTO t1 VALUES(X'78',x'79',x'7a');
    INSERT INTO t1 VALUES(X'78',NULL,X'7A');
    INSERT INTO t1 VALUES(NULL,NULL,NULL);
    SELECT count(*) FROM t1;
  }
} {7}

# Do an SQL statement.  Append the search count to the end of the result.
#
proc count sql {
  set ::sqlite_search_count 0
  return [concat [execsql $sql] $::sqlite_search_count]
}

# Verify that queries use an index.  We are using the special variable
# "sqlite_search_count" which tallys the number of executions of MoveTo
# and Next operators in the VDBE.  By verifing that the search count is
# small we can be assured that indices are being used properly.
#
do_test where4-1.1 {
  count {SELECT rowid FROM t1 WHERE w IS NULL}
} {7 2}
do_test where4-1.2 {
  count {SELECT rowid FROM t1 WHERE +w IS NULL}
} {7 6}
do_test where4-1.3 {
  count {SELECT rowid FROM t1 WHERE w=1 AND x IS NULL}
} {2 2}
do_test where4-1.4 {
  count {SELECT rowid FROM t1 WHERE w=1 AND +x IS NULL}
} {2 3}
do_test where4-1.5 {
  count {SELECT rowid FROM t1 WHERE w=1 AND x>0}
} {1 2}
do_test where4-1.6 {
  count {SELECT rowid FROM t1 WHERE w=1 AND x<9}
} {1 3}
do_test where4-1.7 {
  count {SELECT rowid FROM t1 WHERE w=1 AND x IS NULL AND y=3}
} {2 2}
do_test where4-1.8 {
  count {SELECT rowid FROM t1 WHERE w=1 AND x IS NULL AND y>2}
} {2 2}
do_test where4-1.9 {
  count {SELECT rowid FROM t1 WHERE w='a' AND x IS NULL AND y='c'}
} {4 2}
do_test where4-1.10 {
  count {SELECT rowid FROM t1 WHERE w=x'78' AND x IS NULL}
} {6 2}
do_test where4-1.11 {
  count {SELECT rowid FROM t1 WHERE w=x'78' AND x IS NULL AND y=123}
} {1}
do_test where4-1.12 {
  count {SELECT rowid FROM t1 WHERE w=x'78' AND x IS NULL AND y=x'7A'}
} {6 2}
do_test where4-1.13 {
  count {SELECT rowid FROM t1 WHERE w IS NULL AND x IS NULL}
} {7 2}
do_test where4-1.14 {
  count {SELECT rowid FROM t1 WHERE w IS NULL AND x IS NULL AND y IS NULL}
} {7 2}
do_test where4-1.15 {
  count {SELECT rowid FROM t1 WHERE w IS NULL AND x IS NULL AND y<0}
} {2}
do_test where4-1.16 {
  count {SELECT rowid FROM t1 WHERE w IS NULL AND x IS NULL AND y>=0}
} {1}

do_test where4-2.1 {
  execsql {SELECT rowid FROM t1 ORDER BY w, x, y}
} {7 2 1 4 3 6 5}
do_test where4-2.2 {
  execsql {SELECT rowid FROM t1 ORDER BY w DESC, x, y}
} {6 5 4 3 2 1 7}
do_test where4-2.3 {
  execsql {SELECT rowid FROM t1 ORDER BY w, x DESC, y}
} {7 1 2 3 4 5 6}


# Ticket #2177
#
# Suppose you have a left join where the right table of the left
# join (the one that can be NULL) has an index on two columns.
# The first indexed column is used in the ON clause of the join.
# The second indexed column is used in the WHERE clause with an IS NULL
# constraint.  It is not allowed to use the IS NULL optimization to
# optimize the query because the second column might be NULL because
# the right table did not match - something the index does not know
# about.
#
do_test where4-3.1 {
  execsql {
    CREATE TABLE t2(a);
    INSERT INTO t2 VALUES(1);
    INSERT INTO t2 VALUES(2);
    INSERT INTO t2 VALUES(3);
    CREATE TABLE t3(x,y,UNIQUE(x,y));
    INSERT INTO t3 VALUES(1,11);
    INSERT INTO t3 VALUES(2,NULL);
 
    SELECT * FROM t2 LEFT JOIN t3 ON a=x WHERE +y IS NULL;
  }
} {2 2 {} 3 {} {}}
do_test where4-3.2 {
  execsql {
    SELECT * FROM t2 LEFT JOIN t3 ON a=x WHERE y IS NULL;
  }
} {2 2 {} 3 {} {}}

# Ticket #2189.  Probably the same bug as #2177.
#
do_test where4-4.1 {
  execsql {
    CREATE TABLE test(col1 TEXT PRIMARY KEY);
    INSERT INTO test(col1) values('a');
    INSERT INTO test(col1) values('b');
    INSERT INTO test(col1) values('c');
    CREATE TABLE test2(col1 TEXT PRIMARY KEY);
    INSERT INTO test2(col1) values('a');
    INSERT INTO test2(col1) values('b');
    INSERT INTO test2(col1) values('c');
    SELECT * FROM test t1 LEFT OUTER JOIN test2 t2 ON t1.col1 = t2.col1
      WHERE +t2.col1 IS NULL;
  }
} {}
do_test where4-4.2 {
  execsql {
    SELECT * FROM test t1 LEFT OUTER JOIN test2 t2 ON t1.col1 = t2.col1
      WHERE t2.col1 IS NULL;
  }
} {}
do_test where4-4.3 {
  execsql {
    SELECT * FROM test t1 LEFT OUTER JOIN test2 t2 ON t1.col1 = t2.col1
      WHERE +t1.col1 IS NULL;
  }
} {}
do_test where4-4.4 {
  execsql {
    SELECT * FROM test t1 LEFT OUTER JOIN test2 t2 ON t1.col1 = t2.col1
      WHERE t1.col1 IS NULL;
  }
} {}
    

integrity_check {where4-99.0}

finish_test