# 2017 April 30
#
# 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.
#
#***********************************************************************
#
# Test the HAVING->WHERE optimization.
#
set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix having
do_execsql_test 1.0 {
CREATE TABLE t2(c, d);
CREATE TABLE t1(a, b);
INSERT INTO t1 VALUES(1, 1);
INSERT INTO t1 VALUES(2, 2);
INSERT INTO t1 VALUES(1, 3);
INSERT INTO t1 VALUES(2, 4);
INSERT INTO t1 VALUES(1, 5);
INSERT INTO t1 VALUES(2, 6);
} {}
foreach {tn sql res} {
1 "SELECT a, sum(b) FROM t1 GROUP BY a HAVING a=2" {2 12}
2 "SELECT a, sum(b) FROM t1 GROUP BY a HAVING a=2 AND sum(b)>10" {2 12}
3 "SELECT a, sum(b) FROM t1 GROUP BY a HAVING sum(b)>12" {}
} {
do_execsql_test 1.$tn $sql $res
}
# Run an EXPLAIN command for both SQL statements. Return true if
# the outputs are identical, or false otherwise.
#
proc compare_vdbe {sql1 sql2} {
set r1 [list]
set r2 [list]
db eval "explain $sql1" { lappend r1 $opcode $p1 $p2 $p3 $p4 $p5}
db eval "explain $sql2" { lappend r2 $opcode $p1 $p2 $p3 $p4 $p5}
return [expr {$r1==$r2}]
}
proc do_compare_vdbe_test {tn sql1 sql2 res} {
uplevel [list do_test $tn [list compare_vdbe $sql1 $sql2] $res]
}
#-------------------------------------------------------------------------
# Test that various statements that are eligible for the optimization
# produce the same VDBE code as optimizing by hand does.
#
foreach {tn sql1 sql2} {
1 "SELECT a, sum(b) FROM t1 GROUP BY a HAVING a=2"
"SELECT a, sum(b) FROM t1 WHERE a=2 GROUP BY a"
2 "SELECT a, sum(b) FROM t1 GROUP BY a HAVING sum(b)>5 AND a=2"
"SELECT a, sum(b) FROM t1 WHERE a=2 GROUP BY a HAVING sum(b)>5"
3 "SELECT a, sum(b) FROM t1 GROUP BY a COLLATE binary HAVING a=2"
"SELECT a, sum(b) FROM t1 WHERE a=2 GROUP BY a COLLATE binary"
5 "SELECT a, sum(b) FROM t1 GROUP BY a COLLATE binary HAVING 0"
"SELECT a, sum(b) FROM t1 WHERE 0 GROUP BY a COLLATE binary"
6 "SELECT count(*) FROM t1,t2 WHERE a=c GROUP BY b, d HAVING b=d"
"SELECT count(*) FROM t1,t2 WHERE a=c AND b=d GROUP BY b, d"
7 {
SELECT count(*) FROM t1,t2 WHERE a=c GROUP BY b, d
HAVING b=d COLLATE nocase
} {
SELECT count(*) FROM t1,t2 WHERE a=c AND b=d COLLATE nocase
GROUP BY b, d
}
8 "SELECT a, sum(b) FROM t1 GROUP BY a||b HAVING substr(a||b, 1, 1)='a'"
"SELECT a, sum(b) FROM t1 WHERE substr(a||b, 1, 1)='a' GROUP BY a||b"
} {
do_compare_vdbe_test 2.$tn $sql1 $sql2 1
}
# The (4) test in the above set used to generate identical bytecode, but
# that is no longer the case. The byte code is equivalent, though.
#
do_execsql_test 2.4a {
SELECT x,y FROM (
SELECT a AS x, sum(b) AS y FROM t1
GROUP BY a
) WHERE x BETWEEN 2 AND 9999
} {2 12}
do_execsql_test 2.4b {
SELECT x,y FROM (
SELECT a AS x, sum(b) AS y FROM t1
WHERE x BETWEEN 2 AND 9999
GROUP BY a
)
} {2 12}
#-------------------------------------------------------------------------
# 1: Test that the optimization is only applied if the GROUP BY term
# uses BINARY collation.
#
# 2: Not applied if there is a non-deterministic function in the HAVING
# term.
#
foreach {tn sql1 sql2} {
1 "SELECT a, sum(b) FROM t1 GROUP BY a COLLATE nocase HAVING a=2"
"SELECT a, sum(b) FROM t1 WHERE a=2 GROUP BY a COLLATE nocase"
2 "SELECT a, sum(b) FROM t1 GROUP BY a HAVING randomblob(a)<X'88'"
"SELECT a, sum(b) FROM t1 WHERE randomblob(a)<X'88' GROUP BY a"
} {
do_compare_vdbe_test 3.$tn $sql1 $sql2 0
}
#-------------------------------------------------------------------------
# Test that non-deterministic functions disqualify a term from being
# moved from the HAVING to WHERE clause.
#
do_execsql_test 4.1 {
CREATE TABLE t3(a, b);
INSERT INTO t3 VALUES(1, 1);
INSERT INTO t3 VALUES(1, 2);
INSERT INTO t3 VALUES(1, 3);
INSERT INTO t3 VALUES(2, 1);
INSERT INTO t3 VALUES(2, 2);
INSERT INTO t3 VALUES(2, 3);
}
proc nondeter {args} {
incr ::nondeter_ret
expr {$::nondeter_ret % 2}
}
db func nondeter nondeter
set ::nondeter_ret 0
do_execsql_test 4.2 {
SELECT a, sum(b) FROM t3 GROUP BY a HAVING nondeter(a)
} {1 6}
# If the term where moved, the query above would return the same
# result as the following. But it does not.
#
set ::nondeter_ret 0
do_execsql_test 4.3 {
SELECT a, sum(b) FROM t3 WHERE nondeter(a) GROUP BY a
} {1 4 2 2}
finish_test