# 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#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#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