Add simple tests (and a fix) for the change on this branch.

FossilOrigin-Name: 897f3f40267dc922f0fda287484435e1fd8709bade3e87c3829e2f945bb5e4aa

test/exists2.test

@@ -0,0 +1,87 @@
+# 2021 January 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 cases where EXISTS expressions are
+# transformed to IN() expressions by where.c
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+set testprefix exists2
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(a INTEGER PRIMARY KEY, b);
+  INSERT INTO t1 VALUES(1, 'one');
+  INSERT INTO t1 VALUES(2, 'two');
+  INSERT INTO t1 VALUES(3, 'three');
+  INSERT INTO t1 VALUES(4, 'four');
+  INSERT INTO t1 VALUES(5, 'five');
+  INSERT INTO t1 VALUES(6, 'six');
+  INSERT INTO t1 VALUES(7, 'seven');
+
+  CREATE TABLE t2(c INTEGER, d INTEGER);
+  INSERT INTO t2 VALUES(1, 1);
+  INSERT INTO t2 VALUES(3, 2);
+  INSERT INTO t2 VALUES(5, 3);
+  INSERT INTO t2 VALUES(7, 4);
+}
+
+proc do_execsql_eqp_test {tn sql eqp res} {
+  uplevel [list do_eqp_test $tn.1 $sql [string trim $eqp]]
+  uplevel [list do_execsql_test $tn.2 $sql $res]
+}
+
+do_execsql_eqp_test 1.1 {
+  SELECT t1.* FROM t1 WHERE EXISTS(SELECT * FROM t2 WHERE t1.a=t2.c);
+} {
+  USING INTEGER PRIMARY KEY
+} {
+  1 one 3 three 5 five 7 seven
+}
+
+do_execsql_eqp_test 1.2 {
+  SELECT t1.* FROM t1 WHERE EXISTS(SELECT * FROM t2 WHERE t2.c=t1.a);
+} {
+  SEARCH TABLE t1 USING INTEGER PRIMARY KEY
+} {
+  1 one 3 three 5 five 7 seven
+}
+
+do_execsql_eqp_test 1.3 {
+  SELECT t1.* FROM t1 WHERE EXISTS(SELECT * FROM t2 WHERE t2.c+1=t1.a);
+} {
+  SEARCH TABLE t1 USING INTEGER PRIMARY KEY
+} {
+  2 two 4 four 6 six
+}
+
+do_execsql_eqp_test 1.4 {
+  SELECT t1.* FROM t1 WHERE EXISTS(SELECT * FROM t2 WHERE t2.c+1=t1.a+1);
+} {
+  SCAN TABLE t1
+} {
+  1 one 3 three 5 five 7 seven
+}
+
+breakpoint
+do_execsql_eqp_test 1.5 {
+  SELECT t1.* FROM t1 WHERE EXISTS(
+    SELECT * FROM t2 WHERE t1.a=t2.c AND d IN (1, 2, 3)
+  );
+} {
+  SEARCH TABLE t1 USING INTEGER PRIMARY KEY
+} {
+  1 one 3 three 5 five
+}
+
+
+
+finish_test