limit.test

sqlite数据库源码

# 2001 November 6
#
# 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 LIMIT ... OFFSET ... clause
#  of SELECT statements.
#
# $Id: limit.test,v 1.11.2.1 2004/07/19 23:33:04 drh Exp $

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

# Build some test data
#
set fd [open data1.txt w]
for {set i 1} {$i<=32} {incr i} {
  for {set j 0} {pow(2,$j)<$i} {incr j} {}
  puts $fd "[expr {32-$i}]\t[expr {10-$j}]"
}
close $fd
execsql {
  CREATE TABLE t1(x int, y int);
  COPY t1 FROM 'data1.txt'
}
file delete data1.txt

do_test limit-1.0 {
  execsql {SELECT count(*) FROM t1}
} {32}
do_test limit-1.1 {
  execsql {SELECT count(*) FROM t1 LIMIT  5}
} {32}
do_test limit-1.2.1 {
  execsql {SELECT x FROM t1 ORDER BY x LIMIT 5}
} {0 1 2 3 4}
do_test limit-1.2.2 {
  execsql {SELECT x FROM t1 ORDER BY x LIMIT 5 OFFSET 2}
} {2 3 4 5 6}
do_test limit-1.2.3 {
  execsql {SELECT x FROM t1 ORDER BY x LIMIT 2, 5}
} {2 3 4 5 6}
do_test limit-1.3 {
  execsql {SELECT x FROM t1 ORDER BY x LIMIT 5 OFFSET 5}
} {5 6 7 8 9}
do_test limit-1.4.1 {
  execsql {SELECT x FROM t1 ORDER BY x LIMIT 50 OFFSET 30}
} {30 31}
do_test limit-1.4.2 {
  execsql {SELECT x FROM t1 ORDER BY x LIMIT 30, 50}
} {30 31}
do_test limit-1.5 {
  execsql {SELECT x FROM t1 ORDER BY x LIMIT 50 OFFSET 50}
} {}
do_test limit-1.6 {
  execsql {SELECT * FROM t1 AS a, t1 AS b ORDER BY a.x, b.x LIMIT 5}
} {0 5 0 5 0 5 1 5 0 5 2 5 0 5 3 5 0 5 4 5}
do_test limit-1.7 {
  execsql {SELECT * FROM t1 AS a, t1 AS b ORDER BY a.x, b.x LIMIT 5 OFFSET 32}
} {1 5 0 5 1 5 1 5 1 5 2 5 1 5 3 5 1 5 4 5}

do_test limit-2.1 {
  execsql {
    CREATE VIEW v1 AS SELECT * FROM t1 LIMIT 2;
    SELECT count(*) FROM (SELECT * FROM v1);
  }
} 2
do_test limit-2.2 {
  execsql {
    CREATE TABLE t2 AS SELECT * FROM t1 LIMIT 2;
    SELECT count(*) FROM t2;
  }
} 2
do_test limit-2.3 {
  execsql {
    SELECT count(*) FROM t1 WHERE rowid IN (SELECT rowid FROM t1 LIMIT 2);
  }
} 2

do_test limit-3.1 {
  execsql {
    SELECT z FROM (SELECT y*10+x AS z FROM t1 ORDER BY x LIMIT 10)
    ORDER BY z LIMIT 5;
  }
} {50 51 52 53 54}

do_test limit-4.1 {
  execsql {
    BEGIN;
    CREATE TABLE t3(x);
    INSERT INTO t3 SELECT x FROM t1 ORDER BY x LIMIT 10 OFFSET 1;
    INSERT INTO t3 SELECT x+(SELECT max(x) FROM t3) FROM t3;
    INSERT INTO t3 SELECT x+(SELECT max(x) FROM t3) FROM t3;
    INSERT INTO t3 SELECT x+(SELECT max(x) FROM t3) FROM t3;
    INSERT INTO t3 SELECT x+(SELECT max(x) FROM t3) FROM t3;
    INSERT INTO t3 SELECT x+(SELECT max(x) FROM t3) FROM t3;
    INSERT INTO t3 SELECT x+(SELECT max(x) FROM t3) FROM t3;
    INSERT INTO t3 SELECT x+(SELECT max(x) FROM t3) FROM t3;
    INSERT INTO t3 SELECT x+(SELECT max(x) FROM t3) FROM t3;
    INSERT INTO t3 SELECT x+(SELECT max(x) FROM t3) FROM t3;
    INSERT INTO t3 SELECT x+(SELECT max(x) FROM t3) FROM t3;
    END;
    SELECT count(*) FROM t3;
  }
} {10240}
do_test limit-4.2 {
  execsql {
    SELECT x FROM t3 LIMIT 2 OFFSET 10000
  }
} {10001 10002}
do_test limit-4.3 {
  execsql {
    CREATE TABLE t4 AS SELECT x,
       'abcdefghijklmnopqrstuvwyxz ABCDEFGHIJKLMNOPQRSTUVWYXZ' || x ||
       'abcdefghijklmnopqrstuvwyxz ABCDEFGHIJKLMNOPQRSTUVWYXZ' || x ||
       'abcdefghijklmnopqrstuvwyxz ABCDEFGHIJKLMNOPQRSTUVWYXZ' || x ||
       'abcdefghijklmnopqrstuvwyxz ABCDEFGHIJKLMNOPQRSTUVWYXZ' || x ||
       'abcdefghijklmnopqrstuvwyxz ABCDEFGHIJKLMNOPQRSTUVWYXZ' || x AS y
    FROM t3 LIMIT 1000;
    SELECT x FROM t4 ORDER BY y DESC LIMIT 1 OFFSET 999;
  }
} {1000}

do_test limit-5.1 {
  execsql {
    CREATE TABLE t5(x,y);
    INSERT INTO t5 SELECT x-y, x+y FROM t1 WHERE x BETWEEN 10 AND 15
        ORDER BY x LIMIT 2;
    SELECT * FROM t5 ORDER BY x;
  }
} {5 15 6 16}
do_test limit-5.2 {
  execsql {
    DELETE FROM t5;
    INSERT INTO t5 SELECT x-y, x+y FROM t1 WHERE x BETWEEN 10 AND 15
        ORDER BY x DESC LIMIT 2;
    SELECT * FROM t5 ORDER BY x;
  }
} {9 19 10 20}
do_test limit-5.3 {
  execsql {
    DELETE FROM t5;
    INSERT INTO t5 SELECT x-y, x+y FROM t1 WHERE x ORDER BY x DESC LIMIT 31;
    SELECT * FROM t5 ORDER BY x LIMIT 2;
  }
} {-4 6 -3 7}
do_test limit-5.4 {
  execsql {
    SELECT * FROM t5 ORDER BY x DESC, y DESC LIMIT 2;
  }
} {21 41 21 39}
do_test limit-5.5 {
  execsql {
    DELETE FROM t5;
    INSERT INTO t5 SELECT a.x*100+b.x, a.y*100+b.y FROM t1 AS a, t1 AS b
                   ORDER BY 1, 2 LIMIT 1000;
    SELECT count(*), sum(x), sum(y), min(x), max(x), min(y), max(y) FROM t5;
  }
} {1000 1528204 593161 0 3107 505 1005}

# There is some contraversy about whether LIMIT 0 should be the same as
# no limit at all or if LIMIT 0 should result in zero output rows.
#
do_test limit-6.1 {
  execsql {
    BEGIN;
    CREATE TABLE t6(a);
    INSERT INTO t6 VALUES(1);
    INSERT INTO t6 VALUES(2);
    INSERT INTO t6 SELECT a+2 FROM t6;
    COMMIT;
    SELECT * FROM t6;
  }
} {1 2 3 4}
do_test limit-6.2 {
  execsql {
    SELECT * FROM t6 LIMIT -1 OFFSET -1;
  }
} {1 2 3 4}
do_test limit-6.3 {
  execsql {
    SELECT * FROM t6 LIMIT 2 OFFSET -123;
  }
} {1 2}
do_test limit-6.4 {
  execsql {
    SELECT * FROM t6 LIMIT -432 OFFSET 2;
  }
} {3 4}
do_test limit-6.5 {
  execsql {
    SELECT * FROM t6 LIMIT -1
  }
} {1 2 3 4}
do_test limit-6.6 {
  execsql {
    SELECT * FROM t6 LIMIT -1 OFFSET 1
  }
} {2 3 4}
do_test limit-6.7 {
  execsql {
    SELECT * FROM t6 LIMIT 0
  }
} {}
do_test limit-6.8 {
  execsql {
    SELECT * FROM t6 LIMIT 0 OFFSET 1
  }
} {}

# Make sure LIMIT works well with compound SELECT statements.
# Ticket #393
#
do_test limit-7.1.1 {
  catchsql {
    SELECT x FROM t2 LIMIT 5 UNION ALL SELECT a FROM t6;
  }
} {1 {LIMIT clause should come after UNION ALL not before}}
do_test limit-7.1.2 {
  catchsql {
    SELECT x FROM t2 LIMIT 5 UNION SELECT a FROM t6;
  }
} {1 {LIMIT clause should come after UNION not before}}
do_test limit-7.1.3 {
  catchsql {
    SELECT x FROM t2 LIMIT 5 EXCEPT SELECT a FROM t6 LIMIT 3;
  }
} {1 {LIMIT clause should come after EXCEPT not before}}
do_test limit-7.1.4 {
  catchsql {
    SELECT x FROM t2 LIMIT 0,5 INTERSECT SELECT a FROM t6;
  }
} {1 {LIMIT clause should come after INTERSECT not before}}
do_test limit-7.2 {
  execsql {
    SELECT x FROM t2 UNION ALL SELECT a FROM t6 LIMIT 5;
  }
} {31 30 1 2 3}
do_test limit-7.3 {
  execsql {
    SELECT x FROM t2 UNION ALL SELECT a FROM t6 LIMIT 3 OFFSET 1;
  }
} {30 1 2}
do_test limit-7.4 {
  execsql {
    SELECT x FROM t2 UNION ALL SELECT a FROM t6 ORDER BY 1 LIMIT 3 OFFSET 1;
  }
} {2 3 4}
do_test limit-7.5 {
  execsql {
    SELECT x FROM t2 UNION SELECT x+2 FROM t2 LIMIT 2 OFFSET 1;
  }
} {31 32}
do_test limit-7.6 {
  execsql {
    SELECT x FROM t2 UNION SELECT x+2 FROM t2 ORDER BY 1 DESC LIMIT 2 OFFSET 1;
  }
} {32 31}
do_test limit-7.7 {
  execsql {
    SELECT a+9 FROM t6 EXCEPT SELECT y FROM t2 LIMIT 2;
  }
} {11 12}
do_test limit-7.8 {
  execsql {
    SELECT a+9 FROM t6 EXCEPT SELECT y FROM t2 ORDER BY 1 DESC LIMIT 2;
  }
} {13 12}
do_test limit-7.9 {
  execsql {
    SELECT a+26 FROM t6 INTERSECT SELECT x FROM t2 LIMIT 1;
  }
} {30}
do_test limit-7.10 {
  execsql {
    SELECT a+27 FROM t6 INTERSECT SELECT x FROM t2 LIMIT 1;
  }
} {30}
do_test limit-7.11 {
  execsql {
    SELECT a+27 FROM t6 INTERSECT SELECT x FROM t2 LIMIT 1 OFFSET 1;
  }
} {31}
do_test limit-7.12 {
  execsql {
    SELECT a+27 FROM t6 INTERSECT SELECT x FROM t2 
       ORDER BY 1 DESC LIMIT 1 OFFSET 1;
  }
} {30}

# Tests for limit in conjunction with distinct.  The distinct should
# occur before both the limit and the offset.  Ticket #749.
#
do_test limit-8.1 {
  execsql {
    SELECT DISTINCT round(x/100) FROM t3 LIMIT 5;
  }
} {0 1 2 3 4}
do_test limit-8.2 {
  execsql {
    SELECT DISTINCT round(x/100) FROM t3 LIMIT 5 OFFSET 5;
  }
} {5 6 7 8 9}
do_test limit-8.3 {
  execsql {
    SELECT DISTINCT round(x/100) FROM t3 LIMIT 5 OFFSET 25;
  }
} {25 26 27 28 29}


finish_test