USE test;
#
# MDEV-14013 : sql_mode=EMPTY_STRING_IS_NULL
#
set @mode='EMPTY_STRING_IS_NULL';
SET SESSION character_set_connection=latin2;
SET SESSION character_set_client=cp1250;
#
# Test litteral
#
SET sql_mode=@mode;
select @@sql_mode;
@@sql_mode
EMPTY_STRING_IS_NULL
SELECT '',CHARSET(''), null, CHARSET(null), CAST(null as char(10)), CHARSET(CAST(null as char(10))), 'x', CHARSET('x');
NULL	CHARSET('')	NULL	CHARSET(null)	CAST(null as char(10))	CHARSET(CAST(null as char(10)))	x	CHARSET('x')
NULL	latin2	NULL	binary	NULL	latin2	x	latin2
SELECT CHARSET(NULLIF('','')),NULLIF('','');
CHARSET(NULLIF('',''))	NULLIF('','')
latin2	NULL
SET sql_mode=default;
SELECT '',CHARSET(''), null, CHARSET(null), CAST(null as char(10)), CHARSET(CAST(null as char(10))), 'x', CHARSET('x');
	CHARSET('')	NULL	CHARSET(null)	CAST(null as char(10))	CHARSET(CAST(null as char(10)))	x	CHARSET('x')
	latin2	NULL	binary	NULL	latin2	x	latin2
SELECT CHARSET(NULLIF('','')),NULLIF('','');
CHARSET(NULLIF('',''))	NULLIF('','')
latin2	NULL
#
# Test NCHAR litteral
#
SET sql_mode=@mode;
SELECT N'',CHARSET(N''), N'x', CHARSET(N'x');
NULL	CHARSET(N'')	x	CHARSET(N'x')
NULL	utf8	x	utf8
SELECT CHARSET(NULLIF(N'',N'')),NULLIF(N'',N'');
CHARSET(NULLIF(N'',N''))	NULLIF(N'',N'')
utf8	NULL
SET sql_mode=default;
SELECT N'',CHARSET(N''), N'x', CHARSET(N'x');
	CHARSET(N'')	x	CHARSET(N'x')
	utf8	x	utf8
SELECT CHARSET(NULLIF(N'',N'')),NULLIF(N'',N'');
CHARSET(NULLIF(N'',N''))	NULLIF(N'',N'')
utf8	NULL
#
# Test CHARSET prefix litteral
#
SET sql_mode=@mode;
SELECT _cp1250 '',CHARSET(_cp1250 ''), _cp1250 'x', CHARSET(_cp1250 'x');
NULL	CHARSET(_cp1250 '')	x	CHARSET(_cp1250 'x')
NULL	cp1250	x	cp1250
SELECT CHARSET(NULLIF(_cp1250 '',_cp1250 '')),NULLIF(_cp1250 '',_cp1250 '');
CHARSET(NULLIF(_cp1250 '',_cp1250 ''))	NULLIF(_cp1250 '',_cp1250 '')
cp1250	NULL
SET sql_mode=default;
SELECT _cp1250 '',CHARSET(_cp1250 ''), _cp1250 'x', CHARSET(_cp1250 'x');
	CHARSET(_cp1250 '')	x	CHARSET(_cp1250 'x')
	cp1250	x	cp1250
SELECT CHARSET(NULLIF(_cp1250 '',_cp1250 '')),NULLIF(_cp1250 '',_cp1250 '');
CHARSET(NULLIF(_cp1250 '',_cp1250 ''))	NULLIF(_cp1250 '',_cp1250 '')
cp1250	NULL
SET sql_mode=@mode;
#
# Test litteral concat
#
SELECT 'a' 'b';
a
ab
SELECT 'a' '';
a
a
SELECT '' 'b';
b
b
SELECT '' '';
NULL
NULL
SELECT '' 'b' 'c';
b
bc
SELECT '' '' 'c';
c
c
SELECT 'a' '' 'c';
a
ac
SELECT 'a' '' '';
a
a
SELECT '' '' '';
NULL
NULL
SELECT '' '' '',CHARSET('' '' '');
NULL	CHARSET('' '' '')
NULL	latin2
SELECT _latin1'' '' '',CHARSET(_latin1'' '' '');
NULL	CHARSET(_latin1'' '' '')
NULL	latin1
SELECT N'' '' '',CHARSET(N'' '' '');
NULL	CHARSET(N'' '' '')
NULL	utf8
#
# UNION - implicit group by
#
SELECT 1, null
UNION
SELECT 1 , ''
ORDER BY 1;
1	NULL
1	NULL
SELECT 1, null
UNION
SELECT 1 , N''
ORDER BY 1;
1	NULL
1	NULL
SELECT 1, null
UNION
SELECT 1 , _cp1250 ''
ORDER BY 1;
1	NULL
1	NULL
SELECT NULLIF(_cp1250 '',_cp1250 '')
UNION
SELECT NULLIF(N'',N'');
NULLIF(_cp1250 '',_cp1250 '')
NULL
SELECT 1 , _latin2 ''
UNION
SELECT 1 , _cp1250 '';
ERROR HY000: Illegal mix of collations (latin2_general_ci,IGNORABLE) and (cp1250_general_ci,IGNORABLE) for operation 'UNION'
SELECT 1, null
UNION
SELECT 1 , ''
UNION
SELECT 1 , N'';
1	NULL
1	NULL
CREATE TABLE t1 (c1 INT,c2 VARCHAR(10));
INSERT INTO t1 VALUES (1,'one');
INSERT INTO t1 VALUES (1,'');
INSERT INTO t1 VALUES (1,null);
#
# Test in a view
#
CREATE VIEW v1
AS SELECT c1, c2
FROM t1
UNION
SELECT c1 , ''
         FROM t1
ORDER BY 1,2;
SELECT * FROM v1;
c1	c2
1	NULL
1	one
SHOW CREATE VIEW v1;
View	Create View	character_set_client	collation_connection
v1	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v1` AS select `t1`.`c1` AS `c1`,`t1`.`c2` AS `c2` from `t1` union select `t1`.`c1` AS `c1`,NULL AS `NULL` from `t1` order by 1,2	cp1250	latin2_general_ci
DROP VIEW v1;
DROP TABLE t1;
EXPLAIN EXTENDED SELECT '';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
Warnings:
Note	1003	select NULL AS `NULL`
EXPLAIN EXTENDED SELECT _latin1'';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
Warnings:
Note	1003	select NULL AS `NULL`
EXPLAIN EXTENDED SELECT N'';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
Warnings:
Note	1003	select NULL AS `NULL`
EXPLAIN EXTENDED SELECT '' '';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
Warnings:
Note	1003	select NULL AS `NULL`