SQLite

# 2008 June 24
#
# 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. 
#
# $Id: select9.test,v 1.3 2008/06/30 07:53:10 danielk1977 Exp $

# The tests in this file are focused on test compound SELECT statements 
# that have any or all of an ORDER BY, LIMIT or OFFSET clauses. As of
# version 3.6.0, SQLite contains code to use SQL indexes where possible 
# to optimize such statements.
#

  } {4 5 6 7}

  test_compound_select select9-2.$iOuterLoop.4 {
    SELECT a FROM t1 WHERE a<8 INTERSECT SELECT d FROM t2 WHERE d<=3 ORDER BY 1
  } {1 2 3}

}

do_test select9-2.X {
  execsql {
    DROP INDEX i1;
    DROP INDEX i2;
    DROP INDEX i3;
  }
} {}

# This procedure executes the SQL.  Then it checks the generated program
# for the SQL and appends a "nosort" to the result if the program contains the
# SortCallback opcode.  If the program does not contain the SortCallback
# opcode it appends "sort"
#
proc cksort {sql} {
  set ::sqlite_sort_count 0
  set data [execsql $sql]
  if {$::sqlite_sort_count} {set x sort} {set x nosort}
  lappend data $x
  return $data
}

# If the right indexes exist, the following query:
#
#     SELECT t1.a FROM t1 UNION ALL SELECT t2.d FROM t2 ORDER BY 1
#
# can use indexes to run without doing a in-memory sort operation.
# This block of tests (select9-3.*) is used to check if the same 
# is possible with:
#
#     CREATE VIEW v1 AS SELECT a FROM t1 UNION ALL SELECT d FROM t2
#     SELECT a FROM v1 ORDER BY 1
#
# Currently it is not.
#
do_test select9-3.1 {
  cksort { SELECT a FROM t1 ORDER BY 1 }
} {1 2 3 4 5 6 7 8 9 10 sort}
do_test select9-3.2 {
  execsql { CREATE INDEX i1 ON t1(a) }
  cksort { SELECT a FROM t1 ORDER BY 1 }
} {1 2 3 4 5 6 7 8 9 10 nosort}
do_test select9-3.3 {
  cksort { SELECT a FROM t1 UNION ALL SELECT d FROM t2 ORDER BY 1 LIMIT 5 }
} {1 1 2 2 3 sort}
do_test select9-3.4 {
  execsql { CREATE INDEX i2 ON t2(d) }
  cksort { SELECT a FROM t1 UNION ALL SELECT d FROM t2 ORDER BY 1 LIMIT 5 }
} {1 1 2 2 3 nosort}
do_test select9-3.5 {
  execsql { CREATE VIEW v1 AS SELECT a FROM t1 UNION ALL SELECT d FROM t2 }
  cksort { SELECT a FROM v1 ORDER BY 1 LIMIT 5 }
} {1 1 2 2 3 sort}
do_test select9-3.X {
  execsql {
    DROP INDEX i1;
    DROP INDEX i2;
    DROP VIEW v1;
  }
} {}

# This block of tests is the same as the preceding one, except that
# "UNION" is tested instead of "UNION ALL".
#
do_test select9-4.1 {
  cksort { SELECT a FROM t1 ORDER BY 1 }
} {1 2 3 4 5 6 7 8 9 10 sort}
do_test select9-4.2 {
  execsql { CREATE INDEX i1 ON t1(a) }
  cksort { SELECT a FROM t1 ORDER BY 1 }
} {1 2 3 4 5 6 7 8 9 10 nosort}
do_test select9-4.3 {
  cksort { SELECT a FROM t1 UNION SELECT d FROM t2 ORDER BY 1 LIMIT 5 }
} {1 2 3 4 5 sort}
do_test select9-4.4 {
  execsql { CREATE INDEX i2 ON t2(d) }
  cksort { SELECT a FROM t1 UNION SELECT d FROM t2 ORDER BY 1 LIMIT 5 }
} {1 2 3 4 5 nosort}
do_test select9-4.5 {
  execsql { CREATE VIEW v1 AS SELECT a FROM t1 UNION SELECT d FROM t2 }
  cksort { SELECT a FROM v1 ORDER BY 1 LIMIT 5 }
} {1 2 3 4 5 sort}
do_test select9-4.X {
  execsql {
    DROP INDEX i1;
    DROP INDEX i2;
    DROP VIEW v1;
  }
} {}


finish_test