minmax.test

sqlite-3.4.1,嵌入式数据库.是一个功能强大的开源数据库,给学习和研发以及小型公司的发展带来了全所未有的好处.

# 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 1.19 2006/03/26 01:21:23 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
} {2}
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 {
  ifcapable subquery {
    execsql {INSERT INTO t2 VALUES((SELECT max(a) FROM t2)+1,999)}
  } else {
    db function max_a_t2 {execsql {SELECT max(a) FROM t2}}
    execsql {INSERT INTO t2 VALUES(max_a_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 {
  ifcapable subquery {
    execsql {INSERT INTO t2 VALUES((SELECT max(a) FROM t2)+1,999)}
  } else {
    db function max_a_t2 {execsql {SELECT max(a) FROM t2}}
    execsql {INSERT INTO t2 VALUES(max_a_t2()+1,999)}
  }
  set sqlite_search_count 0
  ifcapable subquery {
    execsql { SELECT b FROM t2 WHERE a=(SELECT max(a) FROM t2) }
  } else {
    execsql { SELECT b FROM t2 WHERE a=max_a_t2() }
  }
} {999}
do_test minmax-3.3 {
  set sqlite_search_count
} {0}

ifcapable {compound && subquery} {
  do_test minmax-4.1 {
    execsql {
      SELECT coalesce(min(x+0),-1), coalesce(max(x+0),-1) FROM
        (SELECT * FROM t1 UNION SELECT NULL as 'x', NULL as 'y')
    }
  } {1 20}
  do_test minmax-4.2 {
    execsql {
      SELECT y, coalesce(sum(x),0) FROM
        (SELECT null AS x, y+1 AS y 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 AS x, y+1 AS y 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}
} ;# ifcapable compound

# 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
  }
} {}

# Make sure the max(x) and min(x) optimizations work for nested
# queries.  Ticket #587.
#
do_test minmax-7.1 {
  execsql {
    SELECT max(x) FROM t1;
  }
} 20
ifcapable subquery {
  do_test minmax-7.2 {
    execsql {
      SELECT * FROM (SELECT max(x) FROM t1);
    }
  } 20
}
do_test minmax-7.3 {
  execsql {
    SELECT min(x) FROM t1;
  }
} 1
ifcapable subquery {
  do_test minmax-7.4 {
    execsql {
      SELECT * FROM (SELECT min(x) FROM t1);
    }
  } 1
}

# Make sure min(x) and max(x) work correctly when the datatype is
# TEXT instead of NUMERIC.  Ticket #623.
#
do_test minmax-8.1 {
  execsql {
    CREATE TABLE t4(a TEXT);
    INSERT INTO t4 VALUES('1234');
    INSERT INTO t4 VALUES('234');
    INSERT INTO t4 VALUES('34');
    SELECT min(a), max(a) FROM t4;
  }
} {1234 34}
do_test minmax-8.2 {
  execsql {
    CREATE TABLE t5(a INTEGER);
    INSERT INTO t5 VALUES('1234');
    INSERT INTO t5 VALUES('234');
    INSERT INTO t5 VALUES('34');
    SELECT min(a), max(a) FROM t5;
  }
} {34 1234}

# Ticket #658:  Test the min()/max() optimization when the FROM clause
# is a subquery.
#
ifcapable {compound && subquery} {
  do_test minmax-9.1 {
    execsql {
      SELECT max(rowid) FROM (
        SELECT max(rowid) FROM t4 UNION SELECT max(rowid) FROM t5
      )
    }
  } {1}
  do_test minmax-9.2 {
    execsql {
      SELECT max(rowid) FROM (
        SELECT max(rowid) FROM t4 EXCEPT SELECT max(rowid) FROM t5
      )
    }
  } {{}}
} ;# ifcapable compound&&subquery

# If there is a NULL in an aggregate max() or min(), ignore it.  An
# aggregate min() or max() will only return NULL if all values are NULL.
#
do_test minmax-10.1 {
  execsql {
    CREATE TABLE t6(x);
    INSERT INTO t6 VALUES(1);
    INSERT INTO t6 VALUES(2);
    INSERT INTO t6 VALUES(NULL);
    SELECT coalesce(min(x),-1) FROM t6;
  }
} {1}
do_test minmax-10.2 {
  execsql {
    SELECT max(x) FROM t6;
  }
} {2}
do_test minmax-10.3 {
  execsql {
    CREATE INDEX i6 ON t6(x);
    SELECT coalesce(min(x),-1) FROM t6;
  }
} {1}
do_test minmax-10.4 {
  execsql {
    SELECT max(x) FROM t6;
  }
} {2}
do_test minmax-10.5 {
  execsql {
    DELETE FROM t6 WHERE x NOT NULL;
    SELECT count(*) FROM t6;
  }
} 1
do_test minmax-10.6 {
  execsql {
    SELECT count(x) FROM t6;
  }
} 0
ifcapable subquery {
  do_test minmax-10.7 {
    execsql {
      SELECT (SELECT min(x) FROM t6), (SELECT max(x) FROM t6);
    }
  } {{} {}}
}
do_test minmax-10.8 {
  execsql {
    SELECT min(x), max(x) FROM t6;
  }
} {{} {}}
do_test minmax-10.9 {
  execsql {
    INSERT INTO t6 SELECT * FROM t6;
    INSERT INTO t6 SELECT * FROM t6;
    INSERT INTO t6 SELECT * FROM t6;
    INSERT INTO t6 SELECT * FROM t6;
    INSERT INTO t6 SELECT * FROM t6;
    INSERT INTO t6 SELECT * FROM t6;
    INSERT INTO t6 SELECT * FROM t6;
    INSERT INTO t6 SELECT * FROM t6;
    INSERT INTO t6 SELECT * FROM t6;
    INSERT INTO t6 SELECT * FROM t6;
    SELECT count(*) FROM t6;
  }
} 1024
do_test minmax-10.10 {
  execsql {
    SELECT count(x) FROM t6;
  }
} 0
ifcapable subquery {
  do_test minmax-10.11 {
    execsql {
      SELECT (SELECT min(x) FROM t6), (SELECT max(x) FROM t6);
    }
  } {{} {}}
}
do_test minmax-10.12 {
  execsql {
    SELECT min(x), max(x) FROM t6;
  }
} {{} {}}


finish_test