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CREATE TABLE t1(id INT); INSERT INTO t1 VALUES (1),(2),(3),(4); INSERT INTO t1 SELECT a.id FROM t1 a,t1 b,t1 c,t1 d; SET SESSION debug="d,subselect_exec_fail"; SELECT SUM(EXISTS(SELECT RAND() FROM t1)) FROM t1; SUM(EXISTS(SELECT RAND() FROM t1)) 0 SELECT REVERSE(EXISTS(SELECT RAND() FROM t1)); REVERSE(EXISTS(SELECT RAND() FROM t1)) 0 SET SESSION debug=DEFAULT; DROP TABLE t1; |