^^&&^^

Edit File: user_var.test

# Initialise
--disable_warnings
drop table if exists t1,t2;
--enable_warnings

--error 1054
set @a := foo;
set @a := connection_id() + 3;
select @a - connection_id();

set @b := 1;
select @b;

# Check using and setting variables with SELECT DISTINCT

CREATE TABLE t1 ( i int not null, v int not null,index (i));
insert into t1 values (1,1),(1,3),(2,1); 
create table t2 (i int not null, unique (i));
insert into t2 select distinct i from t1;
select * from t2; 
select distinct t2.i,@vv1:=if(sv1.i,1,0),@vv2:=if(sv2.i,1,0),@vv3:=if(sv3.i,1,0), @vv1+@vv2+@vv3 from t2 left join t1 as sv1 on sv1.i=t2.i and sv1.v=1 left join t1 as sv2 on sv2.i=t2.i and sv2.v=2 left join t1 as sv3 on sv3.i=t2.i and sv3.v=3;
explain select * from t1 where i=@vv1;
select @vv1,i,v from t1 where i=@vv1;
explain select * from t1 where @vv1:=@vv1+1 and i=@vv1;
explain select @vv1:=i from t1 where i=@vv1;
explain select * from t1 where i=@vv1;
drop table t1,t2;

# Check types of variables
set @a=0,@b=0;
select @a:=10,   @b:=1,   @a > @b, @a < @b;
# Note that here a and b will be avaluated as number
select @a:="10", @b:="1", @a > @b, @a < @b;
# Note that here a and b will be avaluated as strings
select @a:=10,   @b:=2,   @a > @b, @a < @b;
select @a:="10", @b:="2", @a > @b, @a < @b;

# Fixed bug #1194
select @a:=1;
select @a, @a:=1;

create table t1 (id int, d double, c char(10));
insert into t1 values (1,2.0, "test");
select @c:=0;
update t1 SET id=(@c:=@c+1);
select @c;
select @c:=0;
update t1 set id=(@c:=@c+1);
select @c;
select @c:=0;
select @c:=@c+1;
select @d,(@d:=id),@d from t1;
select @e,(@e:=d),@e from t1;
select @f,(@f:=c),@f from t1;
set @g=1;
select @g,(@g:=c),@g from t1;
select @c, @d, @e, @f;
select @d:=id, @e:=id, @f:=id, @g:=@id from t1;
select @c, @d, @e, @f, @g;
drop table t1;

# just for fun :)
select @a:=10, @b:=2, @a>@b, @a:="10", @b:="2", @a>@b, @a:=10, @b:=2, @a>@b, @a:="10", @b:="2", @a>@b;

#
# bug#1739
# Item_func_set_user_var sets update_query_id, Item_func_get_user_var checks it
#
create table t1 (i int not null);
insert t1 values (1),(2),(2),(3),(3),(3);
select @a:=0; select @a, @a:=@a+count(*), count(*), @a from t1 group by i;
select @a:=0; select @a+0, @a:=@a+0+count(*), count(*), @a+0 from t1 group by i;

set @a=0;
select @a,@a:="hello",@a,@a:=3,@a,@a:="hello again" from t1 group by i;
select @a,@a:="hello",@a,@a:=3,@a,@a:="hello again" from t1 group by i;
drop table t1;

#
# Bug #2244: User variables didn't copy collation and derivation
# attributes from values they were initialized to.
#

set @a=_latin2'test';
select charset(@a),collation(@a),coercibility(@a);
select @a=_latin2'TEST';
select @a=_latin2'TEST' collate latin2_bin;

set @a=_latin2'test' collate latin2_general_ci;
select charset(@a),collation(@a),coercibility(@a);
select @a=_latin2'TEST';
select @a=_latin2'TEST' collate latin2_bin;

#
# Check the same invoking Item_set_user_var
#
select charset(@a:=_latin2'test');
select collation(@a:=_latin2'test');
select coercibility(@a:=_latin2'test');
select collation(@a:=_latin2'test' collate latin2_bin);
select coercibility(@a:=_latin2'test' collate latin2_bin);
select (@a:=_latin2'test' collate latin2_bin) = _latin2'TEST';
select charset(@a),collation(@a),coercibility(@a);
select (@a:=_latin2'test' collate latin2_bin) = _latin2'TEST' collate latin2_general_ci;

#
# Bug #6321 strange error:
#   string function FIELD(<uservariable content NULL>, ...)
#
set @var= NULL ;
select FIELD( @var,'1it','Hit') as my_column;

#
# Bug#9425 A user variable doesn't always have implicit coercibility
#
select @v, coercibility(@v);
set @v1=null, @v2=1, @v3=1.1, @v4=now();
select coercibility(@v1),coercibility(@v2),coercibility(@v3),coercibility(@v4);

#
# Bug #9286  SESSION/GLOBAL should be disallowed for user variables
#
--error 1064
set session @honk=99;

#
# Bug #10724  @@local not preserved in column name of select
#
# The value doesn't actually matter, we just care about the column name
--replace_column 1 #
select @@local.max_allowed_packet;
--replace_column 1 #
select @@session.max_allowed_packet;
--replace_column 1 #
select @@global.max_allowed_packet;
--replace_column 1 #
select @@max_allowed_packet;
--replace_column 1 #
select @@Max_Allowed_Packet;
--replace_column 1 #
select @@version;
--replace_column 1 #
select @@global.version;

--echo End of 4.1 tests

# Bug #6598: problem with cast(NULL as signed integer);
#

set @first_var= NULL;
create table t1 select @first_var;
show create table t1;
drop table t1;
set @first_var= cast(NULL as signed integer);
create table t1 select @first_var;
show create table t1;
drop table t1;
set @first_var= NULL;
create table t1 select @first_var;
show create table t1;
drop table t1;
set @first_var= concat(NULL);
create table t1 select @first_var;
show create table t1;
drop table t1;
set @first_var=1;
set @first_var= cast(NULL as CHAR);
create table t1 select @first_var;
show create table t1;
drop table t1;

#
# Bug #7498 User variable SET saves SIGNED BIGINT as UNSIGNED BIGINT
#

# First part, set user var to large number and select it
set @a=18446744071710965857;
select @a;

# Second part, set user var from large number in table
# then select it
CREATE TABLE `bigfailure` (
  `afield` BIGINT UNSIGNED NOT NULL
);
INSERT INTO `bigfailure` VALUES (18446744071710965857);
SELECT * FROM bigfailure;
select * from (SELECT afield FROM bigfailure) as b;
select * from bigfailure where afield = (SELECT afield FROM bigfailure);
select * from bigfailure where afield = 18446744071710965857;
# This is fixed in 5.0, to be uncommented there
#select * from bigfailure where afield = '18446744071710965857';
select * from bigfailure where afield = 18446744071710965856+1;

SET @a := (SELECT afield FROM bigfailure);
SELECT @a;
SET @a := (select afield from (SELECT afield FROM bigfailure) as b);
SELECT @a;
SET @a := (select * from bigfailure where afield = (SELECT afield FROM bigfailure));
SELECT @a;

drop table bigfailure;

#
# Bug#16861: User defined variable can have a wrong value if a tmp table was
#            used.
#
create table t1(f1 int, f2 int);
insert into t1 values (1,2),(2,3),(3,1);
select @var:=f2 from t1 group by f1 order by f2 desc limit 1;
select @var;
create table t2 as select @var:=f2 from t1 group by f1 order by f2 desc limit 1;
select * from t2;
select @var;
drop table t1,t2;

#
# Bug#19024 - SHOW COUNT(*) WARNINGS not return Errors 
#
--error 1064
insert into city 'blah';
SHOW COUNT(*) WARNINGS;
SHOW COUNT(*) ERRORS;

#
# Bug#28494: Grouping by Item_func_set_user_var produces incorrect result.
#
create table t1(f1 int, f2 varchar(2), f3 float, f4 decimal(2,1));
insert into t1 values 
  (1, "a", 1.5, 1.6), (1, "a", 1.5, 1.6), (2, "b", 2.5, 2.6),
  (3, "c", 3.5, 3.6), (4, "d", 4.5, 4.6), (1, "a", 1.5, 1.6),
  (3, "c", 3.5, 3.6), (1, "a", 1.5, 1.6);
select @a:=f1, count(f1) from t1 group by 1 desc;
select @a:=f1, count(f1) from t1 group by 1 asc;
select @a:=f2, count(f2) from t1 group by 1 desc;
select @a:=f3, count(f3) from t1 group by 1 desc;
select @a:=f4, count(f4) from t1 group by 1 desc;
drop table t1;

#
# Bug#32482: Crash for a query with ORDER BY a user variable.
#
create table t1 (f1 int);
insert into t1 values (2), (1);
select @i := f1 as j from t1 order by 1;
drop table t1;
# Bug #32260: User variables in query cause server crash
#
create table t1(a int);
insert into t1 values(5),(4),(4),(3),(2),(2),(2),(1);
set @rownum := 0;
set @rank := 0;
set @prev_score := NULL;
# Disable the result log as we assign a value to a user variable in one part 
# of a statement and use the same variable in other part of the same statement,
# so we can get unexpected results.
--disable_result_log
select @rownum := @rownum + 1 as row,
 @rank := IF(@prev_score!=a, @rownum, @rank) as rank,
 @prev_score := a as score
from t1 order by score desc;
--enable_result_log
drop table t1;

#
# Bug#26020: User-Defined Variables are not consistent with columns data types
#

create table t1(b bigint);
insert into t1 (b) values (10), (30), (10);
set @var := 0;
select if(b=@var, 999, b) , @var := b from t1  order by b;
drop table t1;

create temporary table t1 (id int);
insert into t1 values (2), (3), (3), (4);
set @lastid=-1;
select @lastid != id, @lastid, @lastid := id from t1;
drop table t1;

create temporary table t1 (id bigint);
insert into t1 values (2), (3), (3), (4);
set @lastid=-1;
select @lastid != id, @lastid, @lastid := id from t1;
drop table t1;

#
# Bug#42009: SELECT into variable gives different results to direct SELECT
#
CREATE TABLE t1(a INT, b INT);
INSERT INTO t1 VALUES (0, 0), (2, 1), (2, 3), (1, 1), (30, 20);
SELECT a, b INTO @a, @b FROM t1 WHERE a=2 AND b=3 GROUP BY a, b;
SELECT @a, @b;
SELECT a, b FROM t1 WHERE a=2 AND b=3 GROUP BY a, b;
DROP TABLE t1;

#
# Bug#47371: reference by same column name
#
CREATE TABLE t1 (f1 int(11) default NULL, f2 int(11) default NULL);
CREATE TABLE t2 (f1 int(11) default NULL, f2 int(11) default NULL, foo int(11));
CREATE TABLE t3 (f1 int(11) default NULL, f2 int(11) default NULL);

INSERT INTO t1 VALUES(10, 10);
INSERT INTO t1 VALUES(10, 10);
INSERT INTO t2 VALUES(10, 10, 10);
INSERT INTO t2 VALUES(10, 10, 10);
INSERT INTO t3 VALUES(10, 10);
INSERT INTO t3 VALUES(10, 10);

SELECT MIN(t2.f1),
@bar:= (SELECT MIN(t3.f2) FROM t3 WHERE t3.f2 > foo)
FROM t1,t2 WHERE t1.f1 = t2.f1 ORDER BY t2.f1;

DROP TABLE t1, t2, t3;

--echo End of 5.0 tests

#
# Bug#42188: crash and/or memory corruption with user variables in trigger
#

CREATE TABLE t1 (i INT);
CREATE TRIGGER t_after_insert AFTER INSERT ON t1 FOR EACH ROW SET @bug42188 = 10;
INSERT INTO t1 VALUES (1);
--change_user root,,test
INSERT INTO t1 VALUES (1);
DROP TABLE t1;

#
# Bug #55615: debug assertion after using variable in assignment and
# referred to
# Bug #55564: crash with user variables, assignments, joins...
#

CREATE TABLE t1(a INT);
INSERT INTO t1 VALUES (0),(0);
--echo # BUG#55615 : should not crash
SELECT (@a:=(SELECT @a:=1 FROM t1 LIMIT 1)) AND COUNT(1) FROM t1 GROUP BY @a;
--echo # BUG#55564 : should not crash
SELECT IF(
  @v:=LEAST((SELECT 1 FROM t1 t2 LEFT JOIN t1 ON (@v) GROUP BY t1.a), a),
  count(*), 1) 
FROM t1 GROUP BY a LIMIT 1;

DROP TABLE t1;

#
# BUG#56138 "valgrind errors about overlapping memory when
# double-assigning same variable"
#

select @v:=@v:=sum(1) from dual;

#
# Bug #57187: more user variable fun with multiple assignments and
#             comparison in query
#

CREATE TABLE t1(a DECIMAL(31,21));
INSERT INTO t1 VALUES (0);

SELECT (@v:=a) <> (@v:=1) FROM t1;

DROP TABLE t1;

--echo End of 5.1 tests

#
# Bug#50511: Sometimes wrong handling of user variables containing NULL.
#

--disable_warnings
DROP TABLE IF EXISTS t1;
--enable_warnings

CREATE TABLE t1(f1 INT AUTO_INCREMENT, PRIMARY KEY(f1));

INSERT INTO t1 SET f1 = NULL ;

SET @aux = NULL ;
INSERT INTO t1 SET f1 = @aux ;

SET @aux1 = 0.123E-1;
SET @aux1 = NULL;
INSERT INTO t1 SET f1 = @aux1 ;

SELECT * FROM t1;

DROP TABLE t1;

CREATE TABLE t1(f1 VARCHAR(257) , f2 INT, PRIMARY KEY(f2));
CREATE TRIGGER trg1 BEFORE INSERT ON t1 FOR EACH ROW SET @aux = 1;

SET @aux = 1; # INT
SET @aux = NULL;
INSERT INTO test.t1 (f1, f2) VALUES (1, 1), (@aux, 2);

SET @aux = 'text'; # STRING
SET @aux = NULL;
INSERT INTO t1(f1, f2) VALUES (1, 3), (@aux, 4);

SELECT f1, f2 FROM t1 ORDER BY f2;

DROP TRIGGER trg1;
DROP TABLE t1;

--echo #
--echo # Bug #12408412: GROUP_CONCAT + ORDER BY + INPUT/OUTPUT
--echo #   SAME USER VARIABLE = CRASH
--echo #

SET @bug12408412=1;
SELECT GROUP_CONCAT(@bug12408412 ORDER BY 1) INTO @bug12408412;

--echo End of 5.5 tests

#
# Bug #11764372 57197: EVEN MORE USER VARIABLE CRASHING FUN
#

CREATE TABLE t1(a int);
INSERT INTO t1 VALUES (1), (2);
SELECT DISTINCT @a:=MIN(t1.a) FROM t1, t1 AS t2
GROUP BY @b:=(SELECT COUNT(*) > t2.a);
DROP TABLE t1;

#
# Bug #11764371 57196: MORE FUN WITH ASSERTION: !TABLE->FILE ||
# TABLE->FILE->INITED == HANDLER::
#

CREATE TABLE t1(a INT) ENGINE=InnoDB;
INSERT INTO t1 VALUES (0);
SELECT DISTINCT POW(COUNT(*), @a:=(SELECT 1 FROM t1 LEFT JOIN t1 AS t2 ON @a))
AS b FROM t1 GROUP BY a;
SELECT @a;
DROP TABLE t1;
CREATE TABLE t1(f1 INT, f2 INT);
INSERT INTO t1 VALUES (1,2),(2,3),(3,1);
CREATE TABLE t2(a INT);
INSERT INTO t2 VALUES (1);
SET @var=NULL;
SELECT @var:=(SELECT f2 FROM t2 WHERE @var) FROM t1 GROUP BY f1 ORDER BY f2 DESC
LIMIT 1;
SELECT @var;
DROP TABLE t1, t2;

#
# Bug#14058892: Extra rows returned when variable is used in subquery in
#               ON clause of RIGHT JOIN
#
CREATE TABLE t1(a INT);
INSERT INTO t1 VALUES (1), (2), (3), (4), (5), (6), (7), (8), (9), (10);

CREATE TABLE t2(a INT);
INSERT INTO t2 VALUES (1), (3), (5), (7), (9);

CREATE TABLE t3(a INT);
INSERT INTO t3 VALUES (1), (4), (7), (10);

SET @var1 = 6;

let $query=
SELECT t1.a, t2.a, t3.a, (@var1:= @var1+0) AS var
FROM t1
     LEFT JOIN t2 ON t1.a=t2.a AND t2.a < @var1
     LEFT JOIN t3 ON t1.a=t3.a AND t3.a < @var1;

eval explain format=json $query;

--sorted_result
eval $query;

DROP TABLE t1, t2, t3;