test/distinct.test

# 2011 July 1
#
# 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 script is the DISTINCT modifier.
#

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

ifcapable !compound {
  finish_test
  return
}

set testprefix distinct


proc is_distinct_noop {sql} {
  set sql1 $sql
  set sql2 [string map {DISTINCT ""} $sql]

  set program1 [list]
  set program2 [list]
  db eval "EXPLAIN $sql1" {
    if {$opcode != "Noop"} { lappend program1 $opcode }
  }
  db eval "EXPLAIN $sql2" {
    if {$opcode != "Noop"} { lappend program2 $opcode }
  }

  return [expr {$program1==$program2}]
}

proc do_distinct_noop_test {tn sql} {
  uplevel [list do_test $tn [list is_distinct_noop $sql] 1]
}
proc do_distinct_not_noop_test {tn sql} {
  uplevel [list do_test $tn [list is_distinct_noop $sql] 0]
}

proc do_temptables_test {tn sql temptables} {
  uplevel [list do_test $tn [subst -novar {
    set ret ""
    db eval "EXPLAIN [set sql]" {
      if {$opcode == "OpenEphemeral" || $opcode == "SorterOpen"} { 
        if {$p5 != "08" && $p5!="00"} { error "p5 = $p5" }
        if {$p5 == "08"} {
          lappend ret hash
        } else {
          lappend ret btree
        }
      }
    }
    set ret
  }] $temptables]
}


#-------------------------------------------------------------------------
# The following tests - distinct-1.* - check that the planner correctly 
# detects cases where a UNIQUE index means that a DISTINCT clause is 
# redundant. Currently the planner only detects such cases when there
# is a single table in the FROM clause.
#
do_execsql_test 1.0 {
  CREATE TABLE t1(a, b, c, d);
  CREATE UNIQUE INDEX i1 ON t1(b, c);
  CREATE UNIQUE INDEX i2 ON t1(d COLLATE nocase);

  CREATE TABLE t2(x INTEGER PRIMARY KEY, y);

  CREATE TABLE t3(c1 PRIMARY KEY NOT NULL, c2 NOT NULL);
  CREATE INDEX i3 ON t3(c2);

  CREATE TABLE t4(a, b NOT NULL, c NOT NULL, d NOT NULL);
  CREATE UNIQUE INDEX t4i1 ON t4(b, c);
  CREATE UNIQUE INDEX t4i2 ON t4(d COLLATE nocase);
}
foreach {tn noop sql} {

  1.1 0   "SELECT DISTINCT b, c FROM t1"
  1.2 1   "SELECT DISTINCT b, c FROM t4"
  2.1 0   "SELECT DISTINCT c FROM t1 WHERE b = ?"
  2.2 1   "SELECT DISTINCT c FROM t4 WHERE b = ?"
  3   1   "SELECT DISTINCT rowid FROM t1"
  4   1   "SELECT DISTINCT rowid, a FROM t1"
  5   1   "SELECT DISTINCT x FROM t2"
  6   1   "SELECT DISTINCT * FROM t2"
  7   1   "SELECT DISTINCT * FROM (SELECT * FROM t2)"

  8.1 0   "SELECT DISTINCT * FROM t1"
  8.2 1   "SELECT DISTINCT * FROM t4"

  8   0   "SELECT DISTINCT a, b FROM t1"

  9   0   "SELECT DISTINCT c FROM t1 WHERE b IN (1,2)"
  10  0   "SELECT DISTINCT c FROM t1"
  11  0   "SELECT DISTINCT b FROM t1"

  12.1 0   "SELECT DISTINCT a, d FROM t1"
  12.2 0   "SELECT DISTINCT a, d FROM t4"
  13.1 0   "SELECT DISTINCT a, b, c COLLATE nocase FROM t1"
  13.2 0   "SELECT DISTINCT a, b, c COLLATE nocase FROM t4"
  14.1 0   "SELECT DISTINCT a, d COLLATE nocase FROM t1"
  14.2 1   "SELECT DISTINCT a, d COLLATE nocase FROM t4"

  15   0   "SELECT DISTINCT a, d COLLATE binary FROM t1"
  16.1 0   "SELECT DISTINCT a, b, c COLLATE binary FROM t1"
  16.2 1   "SELECT DISTINCT a, b, c COLLATE binary FROM t4"

  16  0   "SELECT DISTINCT t1.rowid FROM t1, t2"
  17  0   { /* Technically, it would be possible to detect that DISTINCT
            ** is a no-op in cases like the following. But SQLite does not
            ** do so. */
            SELECT DISTINCT t1.rowid FROM t1, t2 WHERE t1.rowid=t2.rowid }

  18  1   "SELECT DISTINCT c1, c2 FROM t3"
  19  1   "SELECT DISTINCT c1 FROM t3"
  20  1   "SELECT DISTINCT * FROM t3"
  21  0   "SELECT DISTINCT c2 FROM t3"

  22  0   "SELECT DISTINCT * FROM (SELECT 1, 2, 3 UNION SELECT 4, 5, 6)"
  23  1   "SELECT DISTINCT rowid FROM (SELECT 1, 2, 3 UNION SELECT 4, 5, 6)"

  24  0   "SELECT DISTINCT rowid/2 FROM t1"
  25  1   "SELECT DISTINCT rowid/2, rowid FROM t1"
  26.1  0   "SELECT DISTINCT rowid/2, b FROM t1 WHERE c = ?"
  26.2  1   "SELECT DISTINCT rowid/2, b FROM t4 WHERE c = ?"
} {
  if {$noop} {
    do_distinct_noop_test 1.$tn $sql
  } else {
    do_distinct_not_noop_test 1.$tn $sql
  }
}

#-------------------------------------------------------------------------
# The following tests - distinct-2.* - test cases where an index is
# used to deliver results in order of the DISTINCT expressions. 
#
drop_all_tables
do_execsql_test 2.0 {
  CREATE TABLE t1(a, b, c);

  CREATE INDEX i1 ON t1(a, b);
  CREATE INDEX i2 ON t1(b COLLATE nocase, c COLLATE nocase);

  INSERT INTO t1 VALUES('a', 'b', 'c');
  INSERT INTO t1 VALUES('A', 'B', 'C');
  INSERT INTO t1 VALUES('a', 'b', 'c');
  INSERT INTO t1 VALUES('A', 'B', 'C');
}

foreach {tn sql temptables res} {
  1   "a, b FROM t1"                                       {}      {A B a b}
  2   "b, a FROM t1"                                       {}      {B A b a}
  3   "a, b, c FROM t1"                                    {hash}  {a b c A B C}
  4   "a, b, c FROM t1 ORDER BY a, b, c"                   {btree} {A B C a b c}
  5   "b FROM t1 WHERE a = 'a'"                            {}      {b}
  6   "b FROM t1 ORDER BY +b COLLATE binary"          {btree hash} {B b}
  7   "a FROM t1"                                          {}      {A a}
  8   "b COLLATE nocase FROM t1"                           {}      {b}
  9   "b COLLATE nocase FROM t1 ORDER BY b COLLATE nocase" {}      {b}
} {
  do_execsql_test    2.$tn.1 "SELECT DISTINCT $sql" $res
  do_temptables_test 2.$tn.2 "SELECT DISTINCT $sql" $temptables
}

do_execsql_test 2.A {
  SELECT (SELECT DISTINCT o.a FROM t1 AS i) FROM t1 AS o ORDER BY rowid;
} {a A a A}

do_test 3.0 {
  db eval {
    CREATE TABLE t3(a INTEGER, b INTEGER, c, UNIQUE(a,b));
    INSERT INTO t3 VALUES
        (null, null, 1),
        (null, null, 2),
        (null, 3, 4),
        (null, 3, 5),
        (6, null, 7),
        (6, null, 8);
    SELECT DISTINCT a, b FROM t3 ORDER BY +a, +b;
  }
} {{} {} {} 3 6 {}}
do_test 3.1 {
  regexp {OpenEphemeral} [db eval {
    EXPLAIN SELECT DISTINCT a, b FROM t3 ORDER BY +a, +b;
  }]
} {0}

finish_test