mariadb/mysql-test/t/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;
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;