# 2006 January 31

 #

 # 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 join reordering optimization

 # in cases that include a LEFT JOIN.

 #

 # $Id: where3.test,v 1.4 2008/04/17 19:14:02 drh Exp $

 set testdir [file dirname $argv0]

 source $testdir/tester.tcl

 # The following is from ticket #1652.

 #

 # A comma join then a left outer join:  A,B left join C.

 # Arrange indices so that the B table is chosen to go first.

 # Also put an index on C, but make sure that A is chosen before C.

 #

 do_test where3-1.1 {

   execsql {

     CREATE TABLE t1(a, b);

     CREATE TABLE t2(p, q);

     CREATE TABLE t3(x, y);

     INSERT INTO t1 VALUES(111,'one');

     INSERT INTO t1 VALUES(222,'two');

     INSERT INTO t1 VALUES(333,'three');

     INSERT INTO t2 VALUES(1,111);

     INSERT INTO t2 VALUES(2,222);

     INSERT INTO t2 VALUES(4,444);

     CREATE INDEX t2i1 ON t2(p);

     INSERT INTO t3 VALUES(999,'nine');

     CREATE INDEX t3i1 ON t3(x);

     SELECT * FROM t1, t2 LEFT JOIN t3 ON q=x WHERE p=2 AND a=q;

   }

 } {222 two 2 222 {} {}}

 ifcapable explain {

   do_test where3-1.1.1 {

      explain_no_trace {SELECT * FROM t1, t2 LEFT JOIN t3 ON q=x

                         WHERE p=2 AND a=q}

   } [explain_no_trace {SELECT * FROM t1, t2 LEFT JOIN t3 ON x=q

                         WHERE p=2 AND a=q}]

 }

 # Ticket #1830

 #

 # This is similar to the above but with the LEFT JOIN on the

 # other side.

 #

 do_test where3-1.2 {

   execsql {

     CREATE TABLE parent1(parent1key, child1key, Child2key, child3key);

     CREATE TABLE child1 ( child1key NVARCHAR, value NVARCHAR );

     CREATE UNIQUE INDEX PKIDXChild1 ON child1 ( child1key );

     CREATE TABLE child2 ( child2key NVARCHAR, value NVARCHAR );

     INSERT INTO parent1(parent1key,child1key,child2key)

        VALUES ( 1, 'C1.1', 'C2.1' );

     INSERT INTO child1 ( child1key, value ) VALUES ( 'C1.1', 'Value for C1.1' );

     INSERT INTO child2 ( child2key, value ) VALUES ( 'C2.1', 'Value for C2.1' );

     INSERT INTO parent1 ( parent1key, child1key, child2key )

        VALUES ( 2, 'C1.2', 'C2.2' );

     INSERT INTO child2 ( child2key, value ) VALUES ( 'C2.2', 'Value for C2.2' );

     INSERT INTO parent1 ( parent1key, child1key, child2key )

        VALUES ( 3, 'C1.3', 'C2.3' );

     INSERT INTO child1 ( child1key, value ) VALUES ( 'C1.3', 'Value for C1.3' );

     INSERT INTO child2 ( child2key, value ) VALUES ( 'C2.3', 'Value for C2.3' );

     SELECT parent1.parent1key, child1.value, child2.value

     FROM parent1

     LEFT OUTER JOIN child1 ON child1.child1key = parent1.child1key

     INNER JOIN child2 ON child2.child2key = parent1.child2key;

   }

 } {1 {Value for C1.1} {Value for C2.1} 2 {} {Value for C2.2} 3 {Value for C1.3} {Value for C2.3}}

 ifcapable explain {

   do_test where3-1.2.1 {

      explain_no_trace {

        SELECT parent1.parent1key, child1.value, child2.value

        FROM parent1

        LEFT OUTER JOIN child1 ON child1.child1key = parent1.child1key

        INNER JOIN child2 ON child2.child2key = parent1.child2key;

      }

   } [explain_no_trace {

        SELECT parent1.parent1key, child1.value, child2.value

        FROM parent1

        LEFT OUTER JOIN child1 ON parent1.child1key = child1.child1key 

        INNER JOIN child2 ON child2.child2key = parent1.child2key;

      }]

 }

 # This procedure executes the SQL.  Then it appends 

 # the ::sqlite_query_plan variable.

 #

 proc queryplan {sql} {

   set ::sqlite_sort_count 0

   set data [execsql $sql]

   return [concat $data $::sqlite_query_plan]

 }

 # If you have a from clause of the form:   A B C left join D

 # then make sure the query optimizer is able to reorder the 

 # A B C part anyway it wants. 

 #

 # Following the fix to ticket #1652, there was a time when

 # the C table would not reorder.  So the following reorderings

 # were possible:

 #

 #            A B C left join D

 #            B A C left join D

 #

 # But these reorders were not allowed

 #

 #            C A B left join D

 #            A C B left join D

 #            C B A left join D

 #            B C A left join D

 #

 # The following tests are here to verify that the latter four

 # reorderings are allowed again.

 #

 do_test where3-2.1 {

   execsql {

     CREATE TABLE tA(apk integer primary key, ax);

     CREATE TABLE tB(bpk integer primary key, bx);

     CREATE TABLE tC(cpk integer primary key, cx);

     CREATE TABLE tD(dpk integer primary key, dx);

   }

   queryplan {

     SELECT * FROM tA, tB, tC LEFT JOIN tD ON dpk=cx

      WHERE cpk=bx AND bpk=ax

   }

 } {tA {} tB * tC * tD *}

 do_test where3-2.1.1 {

   queryplan {

     SELECT * FROM tA, tB, tC LEFT JOIN tD ON cx=dpk

      WHERE cpk=bx AND bpk=ax

   }

 } {tA {} tB * tC * tD *}

 do_test where3-2.1.2 {

   queryplan {

     SELECT * FROM tA, tB, tC LEFT JOIN tD ON cx=dpk

      WHERE bx=cpk AND bpk=ax

   }

 } {tA {} tB * tC * tD *}

 do_test where3-2.1.3 {

   queryplan {

     SELECT * FROM tA, tB, tC LEFT JOIN tD ON cx=dpk

      WHERE bx=cpk AND ax=bpk

   }

 } {tA {} tB * tC * tD *}

 do_test where3-2.1.4 {

   queryplan {

     SELECT * FROM tA, tB, tC LEFT JOIN tD ON dpk=cx

      WHERE bx=cpk AND ax=bpk

   }

 } {tA {} tB * tC * tD *}

 do_test where3-2.1.5 {

   queryplan {

     SELECT * FROM tA, tB, tC LEFT JOIN tD ON dpk=cx

      WHERE cpk=bx AND ax=bpk

   }

 } {tA {} tB * tC * tD *}

 do_test where3-2.2 {

   queryplan {

     SELECT * FROM tA, tB, tC LEFT JOIN tD ON dpk=cx

      WHERE cpk=bx AND apk=bx

   }

 } {tB {} tA * tC * tD *}

 do_test where3-2.3 {

   queryplan {

     SELECT * FROM tA, tB, tC LEFT JOIN tD ON dpk=cx

      WHERE cpk=bx AND apk=bx

   }

 } {tB {} tA * tC * tD *}

 do_test where3-2.4 {

   queryplan {

     SELECT * FROM tA, tB, tC LEFT JOIN tD ON dpk=cx

      WHERE apk=cx AND bpk=ax

   }

 } {tC {} tA * tB * tD *}

 do_test where3-2.5 {

   queryplan {

     SELECT * FROM tA, tB, tC LEFT JOIN tD ON dpk=cx

      WHERE cpk=ax AND bpk=cx

   }

 } {tA {} tC * tB * tD *}

 do_test where3-2.5 {

   queryplan {

     SELECT * FROM tA, tB, tC LEFT JOIN tD ON dpk=cx

      WHERE bpk=cx AND apk=bx

   }

 } {tC {} tB * tA * tD *}

 do_test where3-2.6 {

   queryplan {

     SELECT * FROM tA, tB, tC LEFT JOIN tD ON dpk=cx

      WHERE cpk=bx AND apk=cx

   }

 } {tB {} tC * tA * tD *}

 finish_test