# # test variables # set @`test`=1,@TEST=3,@select=2; select @test,@`select`,@TEST,@not_used; 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; set @test_int="hello",@test_double="hello",@test_string="hello",@test_string2="hello"; select @test_int,@test_double,@test_string,@test_string2; set @test_int="hellohello",@test_double="hellohello",@test_string="hellohello",@test_string2="hellohello"; select @test_int,@test_double,@test_string,@test_string2; set @test_int=null,@test_double=null,@test_string=null,@test_string2=null; select @test_int,@test_double,@test_string,@test_string2; select @t1:=(@t2:=1)+@t3:=4,@t1,@t2,@t3;