DROP TABLE IF EXISTS t1;
CREATE TABLE t1 (s CHAR(20) PRIMARY KEY, id INT);
INSERT INTO t1 VALUES ('cat', 1), ('mouse', 3), ('dog', 2), ('snake', 77);
SELECT s, id FROM t1 WHERE s = 'mouse';
s	id
mouse	3
drop table t1;
CREATE TABLE t1 (
node int(11) NOT NULL default '0',
maxchild int(11) NOT NULL default '0',
PRIMARY KEY  (`node`)
);
INSERT INTO t1 (node, maxchild) VALUES (4,4),(5,5),(1,244);
SELECT * FROM t1 g1, t1 g2 
WHERE g1.node <= g2.node and g2.node <= g1.maxchild and g2.node = g2.maxchild;
node	maxchild	node	maxchild
4	4	4	4
5	5	5	5
1	244	4	4
1	244	5	5
DROP TABLE t1;