# 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 2.0 3.0 0.5 0.5 0 1} # 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 # ifcapable compound { do_test null-6.1 { execsql { select b from t1 union select c from t1 order by c; } } {{} 0 1} } ;# ifcapable compound # The UNIQUE constraint only applies to non-null values # 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