# 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.

#

# This file implements tests for proper treatment of the special

# value NULL.

#

set testdir [file dirname $argv0]

source $testdir/tester.tcl

# Create a table and some data to work with.

#

do_test null-1.0 {

  execsql {

    begin;

    create table t1(a,b,c);

    insert into t1 values(1,0,0);

    insert into t1 values(2,0,1);

    insert into t1 values(3,1,0);

    insert into t1 values(4,1,1);

    insert into t1 values(5,null,0);

    insert into t1 values(6,null,1);

    insert into t1 values(7,null,null);

    commit;

    select * from t1;

  }

} {1 0 0 2 0 1 3 1 0 4 1 1 5 {} 0 6 {} 1 7 {} {}}

# Check for how arithmetic expressions handle NULL

#

do_test null-1.1 {

  execsql {

    select ifnull(a+b,99) from t1;

  }

} {1 2 4 5 99 99 99}

do_test null-1.2 {

  execsql {

    select ifnull(b*c,99) from t1;

  }

} {0 0 0 1 99 99 99}

# Check to see how the CASE expression handles NULL values.  The

# first WHEN for which the test expression is TRUE is selected.

# FALSE and UNKNOWN test expressions are skipped.

#

do_test null-2.1 {

  execsql {

    select ifnull(case when b<>0 then 1 else 0 end, 99) from t1;

  }

} {0 0 1 1 0 0 0}

do_test null-2.2 {

  execsql {

    select ifnull(case when not b<>0 then 1 else 0 end, 99) from t1;

  }

} {1 1 0 0 0 0 0}

do_test null-2.3 {

  execsql {

    select ifnull(case when b<>0 and c<>0 then 1 else 0 end, 99) from t1;

  }

} {0 0 0 1 0 0 0}

do_test null-2.4 {

  execsql {

    select ifnull(case when not (b<>0 and c<>0) then 1 else 0 end, 99) from t1;

  }

} {1 1 1 0 1 0 0}

do_test null-2.5 {

  execsql {

    select ifnull(case when b<>0 or c<>0 then 1 else 0 end, 99) from t1;

  }

} {0 1 1 1 0 1 0}

do_test null-2.6 {

  execsql {

    select ifnull(case when not (b<>0 or c<>0) then 1 else 0 end, 99) from t1;

  }

} {1 0 0 0 0 0 0}

do_test null-2.7 {

  execsql {

    select ifnull(case b when c then 1 else 0 end, 99) from t1;

  }

} {1 0 0 1 0 0 0}

do_test null-2.8 {

  execsql {

    select ifnull(case c when b then 1 else 0 end, 99) from t1;

  }

} {1 0 0 1 0 0 0}

# Check to see that NULL values are ignored in aggregate functions.

#

do_test null-3.1 {

  execsql {

    select count(*), count(b), count(c), sum(b), sum(c), 

           avg(b), avg(c), min(b), max(b) from t1;

  }

} {7 4 6 2 3 0.5 0.5 0 1}

# The sum of zero entries is a NULL, but the total of zero entries is 0.

#

do_test null-3.2 {

  execsql {

    SELECT sum(b), total(b) FROM t1 WHERE b<0

  }

} {{} 0.0}

# Check to see how WHERE clauses handle NULL values.  A NULL value

# is the same as UNKNOWN.  The WHERE clause should only select those

# rows that are TRUE.  FALSE and UNKNOWN rows are rejected.

#

do_test null-4.1 {

  execsql {

    select a from t1 where b<10

  }

} {1 2 3 4}

do_test null-4.2 {

  execsql {

    select a from t1 where not b>10

  }

} {1 2 3 4}

do_test null-4.3 {

  execsql {

    select a from t1 where b<10 or c=1;

  }

} {1 2 3 4 6}

do_test null-4.4 {

  execsql {

    select a from t1 where b<10 and c=1;

  }

} {2 4}

do_test null-4.5 {

  execsql {

    select a from t1 where not (b<10 and c=1);

  }

} {1 3 5}

# The DISTINCT keyword on a SELECT statement should treat NULL values

# as distinct

#

do_test null-5.1 {

  execsql {

    select distinct b from t1 order by b;

  }

} {{} 0 1}

# A UNION to two queries should treat NULL values

# as distinct.

#

# (Later:)  We also take this opportunity to test the ability

# of an ORDER BY clause to bind to either SELECT of a UNION.

# The left-most SELECT is preferred.  In standard SQL, only

# the left SELECT can be used.  The ability to match an ORDER

# BY term to the right SELECT is an SQLite extension.

#

ifcapable compound {

  do_test null-6.1 {

    execsql {

      select b from t1 union select c from t1 order by b;

    }

  } {{} 0 1}

  do_test null-6.2 {

    execsql {

      select b from t1 union select c from t1 order by 1;

    }

  } {{} 0 1}

  do_test null-6.3 {

    execsql {

      select b from t1 union select c from t1 order by t1.b;

    }

  } {{} 0 1}

  do_test null-6.4 {

    execsql {

      select b from t1 union select c from t1 order by main.t1.b;

    }

  } {{} 0 1}

  do_test null-6.5 {

    catchsql {

      select b from t1 union select c from t1 order by t1.a;

    }

  } {1 {1st ORDER BY term does not match any column in the result set}}

  do_test null-6.6 {

    catchsql {

      select b from t1 union select c from t1 order by main.t1.a;

    }

  } {1 {1st ORDER BY term does not match any column in the result set}}

} ;# ifcapable compound

# The UNIQUE constraint only applies to non-null values

#

ifcapable conflict {

do_test null-7.1 {

    execsql {

      create table t2(a, b unique on conflict ignore);

      insert into t2 values(1,1);

      insert into t2 values(2,null);

      insert into t2 values(3,null);

      insert into t2 values(4,1);

      select a from t2;

    }

  } {1 2 3}

  do_test null-7.2 {

    execsql {

      create table t3(a, b, c, unique(b,c) on conflict ignore);

      insert into t3 values(1,1,1);

      insert into t3 values(2,null,1);

      insert into t3 values(3,null,1);

      insert into t3 values(4,1,1);

      select a from t3;

    }

  } {1 2 3}

}

# Ticket #461 - Make sure nulls are handled correctly when doing a

# lookup using an index.

#

do_test null-8.1 {

  execsql {

    CREATE TABLE t4(x,y);

    INSERT INTO t4 VALUES(1,11);

    INSERT INTO t4 VALUES(2,NULL);

    SELECT x FROM t4 WHERE y=NULL;

  }

} {}

ifcapable subquery {

  do_test null-8.2 {

    execsql {

      SELECT x FROM t4 WHERE y IN (33,NULL);

    }

  } {}

}

do_test null-8.3 {

  execsql {

    SELECT x FROM t4 WHERE y<33 ORDER BY x;

  }

} {1}

do_test null-8.4 {

  execsql {

    SELECT x FROM t4 WHERE y>6 ORDER BY x;

  }

} {1}

do_test null-8.5 {

  execsql {

    SELECT x FROM t4 WHERE y!=33 ORDER BY x;

  }

} {1}

do_test null-8.11 {

  execsql {

    CREATE INDEX t4i1 ON t4(y);

    SELECT x FROM t4 WHERE y=NULL;

  }

} {}

ifcapable subquery {

  do_test null-8.12 {

    execsql {

      SELECT x FROM t4 WHERE y IN (33,NULL);

    }

  } {}

}

do_test null-8.13 {

  execsql {

    SELECT x FROM t4 WHERE y<33 ORDER BY x;

  }

} {1}

do_test null-8.14 {

  execsql {

    SELECT x FROM t4 WHERE y>6 ORDER BY x;

  }

} {1}

do_test null-8.15 {

  execsql {

    SELECT x FROM t4 WHERE y!=33 ORDER BY x;

  }

} {1}

finish_test