minmax.test

SQLite 2.8.6 源代码,用来在Linux/Unix/Windows上编译安装.它是一个小型的数据库,但是非常好用,速度也快,一般的数据库查询之类的操作据统计比MySQL,PostgreSQL

# 2001 September 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 SELECT statements that contain
# aggregate min() and max() functions and which are handled as
# as a special case.
#
# $Id: minmax.test,v 1.6 2003/07/19 00:44:15 drh Exp $

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

do_test minmax-1.0 {
  execsql {
    BEGIN;
    CREATE TABLE t1(x, y);
    INSERT INTO t1 VALUES(1,1);
    INSERT INTO t1 VALUES(2,2);
    INSERT INTO t1 VALUES(3,2);
    INSERT INTO t1 VALUES(4,3);
    INSERT INTO t1 VALUES(5,3);
    INSERT INTO t1 VALUES(6,3);
    INSERT INTO t1 VALUES(7,3);
    INSERT INTO t1 VALUES(8,4);
    INSERT INTO t1 VALUES(9,4);
    INSERT INTO t1 VALUES(10,4);
    INSERT INTO t1 VALUES(11,4);
    INSERT INTO t1 VALUES(12,4);
    INSERT INTO t1 VALUES(13,4);
    INSERT INTO t1 VALUES(14,4);
    INSERT INTO t1 VALUES(15,4);
    INSERT INTO t1 VALUES(16,5);
    INSERT INTO t1 VALUES(17,5);
    INSERT INTO t1 VALUES(18,5);
    INSERT INTO t1 VALUES(19,5);
    INSERT INTO t1 VALUES(20,5);
    COMMIT;
    SELECT DISTINCT y FROM t1 ORDER BY y;
  }
} {1 2 3 4 5}

do_test minmax-1.1 {
  set sqlite_search_count 0
  execsql {SELECT min(x) FROM t1}
} {1}
do_test minmax-1.2 {
  set sqlite_search_count
} {19}
do_test minmax-1.3 {
  set sqlite_search_count 0
  execsql {SELECT max(x) FROM t1}
} {20}
do_test minmax-1.4 {
  set sqlite_search_count
} {19}
do_test minmax-1.5 {
  execsql {CREATE INDEX t1i1 ON t1(x)}
  set sqlite_search_count 0
  execsql {SELECT min(x) FROM t1}
} {1}
do_test minmax-1.6 {
  set sqlite_search_count
} {1}
do_test minmax-1.7 {
  set sqlite_search_count 0
  execsql {SELECT max(x) FROM t1}
} {20}
do_test minmax-1.8 {
  set sqlite_search_count
} {1}
do_test minmax-1.9 {
  set sqlite_search_count 0
  execsql {SELECT max(y) FROM t1}
} {5}
do_test minmax-1.10 {
  set sqlite_search_count
} {19}

do_test minmax-2.0 {
  execsql {
    CREATE TABLE t2(a INTEGER PRIMARY KEY, b);
    INSERT INTO t2 SELECT * FROM t1;
  }
  set sqlite_search_count 0
  execsql {SELECT min(a) FROM t2}
} {1}
do_test minmax-2.1 {
  set sqlite_search_count
} {0}
do_test minmax-2.2 {
  set sqlite_search_count 0
  execsql {SELECT max(a) FROM t2}
} {20}
do_test minmax-2.3 {
  set sqlite_search_count
} {0}

do_test minmax-3.0 {
  execsql {INSERT INTO t2 VALUES((SELECT max(a) FROM t2)+1,999)}
  set sqlite_search_count 0
  execsql {SELECT max(a) FROM t2}
} {21}
do_test minmax-3.1 {
  set sqlite_search_count
} {0}
do_test minmax-3.2 {
  execsql {INSERT INTO t2 VALUES((SELECT max(a) FROM t2)+1,999)}
  set sqlite_search_count 0
  execsql {
    SELECT b FROM t2 WHERE a=(SELECT max(a) FROM t2)
  }
} {999}
do_test minmax-3.3 {
  set sqlite_search_count
} {0}

do_test minmax-4.1 {
  execsql {
    SELECT coalesce(min(x),-1), coalesce(max(x),-1) FROM
      (SELECT * FROM t1 UNION SELECT NULL as 'x', NULL as 'y')
  }
} {1 20}
do_test minmax-4.2 {
  execsql {
    SELECT y, sum(x) FROM
      (SELECT null, y+1 FROM t1 UNION SELECT * FROM t1)
    GROUP BY y ORDER BY y;
  }
} {1 1 2 5 3 22 4 92 5 90 6 0}
do_test minmax-4.3 {
  execsql {
    SELECT y, count(x), count(*) FROM
      (SELECT null, y+1 FROM t1 UNION SELECT * FROM t1)
    GROUP BY y ORDER BY y;
  }
} {1 1 1 2 2 3 3 4 5 4 8 9 5 5 6 6 0 1}

# Make sure the min(x) and max(x) optimizations work on empty tables
# including empty tables with indices. Ticket #296.
#
do_test minmax-5.1 {
  execsql {
    CREATE TABLE t3(x INTEGER UNIQUE NOT NULL);
    SELECT coalesce(min(x),999) FROM t3;
  }
} {999}
do_test minmax-5.2 {
  execsql {
    SELECT coalesce(min(rowid),999) FROM t3;
  }
} {999}
do_test minmax-5.3 {
  execsql {
    SELECT coalesce(max(x),999) FROM t3;
  }
} {999}
do_test minmax-5.4 {
  execsql {
    SELECT coalesce(max(rowid),999) FROM t3;
  }
} {999}
do_test minmax-5.5 {
  execsql {
    SELECT coalesce(max(rowid),999) FROM t3 WHERE rowid<25;
  }
} {999}

# Make sure the min(x) and max(x) optimizations work when there
# is a LIMIT clause.  Ticket #396.
#
do_test minmax-6.1 {
  execsql {
    SELECT min(a) FROM t2 LIMIT 1
  }
} {1}
do_test minmax-6.2 {
  execsql {
    SELECT max(a) FROM t2 LIMIT 3
  }
} {22}
do_test minmax-6.3 {
  execsql {
    SELECT min(a) FROM t2 LIMIT 0,100
  }
} {1}
do_test minmax-6.4 {
  execsql {
    SELECT max(a) FROM t2 LIMIT 1,100
  }
} {}
do_test minmax-6.5 {
  execsql {
    SELECT min(x) FROM t3 LIMIT 1
  }
} {{}}
do_test minmax-6.6 {
  execsql {
    SELECT max(x) FROM t3 LIMIT 0
  }
} {}
do_test minmax-6.7 {
  execsql {
    SELECT max(a) FROM t2 LIMIT 0
  }
} {}


finish_test