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set @`test`=1,@TEST=3,@select=2,@t5=1.23456;
select @test,@`select`,@TEST,@not_used;
@test @`select` @TEST @not_used
1 2 3 NULL
set @test_int=10,@test_double=1e-10,@test_string="abcdeghi",@test_string2="abcdefghij",@select=NULL;
select @test_int,@test_double,@test_string,@test_string2,@select;
@test_int @test_double @test_string @test_string2 @select
10 1e-10 abcdeghi abcdefghij NULL
set @test_int="hello",@test_double="hello",@test_string="hello",@test_string2="hello";
select @test_int,@test_double,@test_string,@test_string2;
@test_int @test_double @test_string @test_string2
hello hello hello hello
set @test_int="hellohello",@test_double="hellohello",@test_string="hellohello",@test_string2="hellohello";
select @test_int,@test_double,@test_string,@test_string2;
@test_int @test_double @test_string @test_string2
hellohello hellohello hellohello hellohello
set @test_int=null,@test_double=null,@test_string=null,@test_string2=null;
select @test_int,@test_double,@test_string,@test_string2;
@test_int @test_double @test_string @test_string2
NULL NULL NULL NULL
select @t1:=(@t2:=1)+@t3:=4,@t1,@t2,@t3;
@t1:=(@t2:=1)+@t3:=4 @t1 @t2 @t3
5 5 1 4
select @t5;
@t5
1.23456
@min_cid:=min(c_id) @max_cid:=max(c_id)
1 4
c_id c_name c_country
1 Bozo USA
4 Mr. Floppy GB
c_id c_name c_country
1 Bozo USA
4 Mr. Floppy GB
c_id c_name c_country
1 Bozo USA
4 Mr. Floppy GB
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