1CREATE TABLE t1(
2a CHAR (255),
3b VARCHAR(255) CHARACTER SET utf8,
4c VARCHAR(255) CHARACTER SET utf8,
5d VARCHAR(255) CHARACTER SET utf8,
6e VARCHAR(255) CHARACTER SET utf8,
7f VARCHAR(4) CHARACTER SET utf8,
8KEY (a),
9KEY (b, c, d, e, f)
10) ENGINE=InnoDB;
11SET big_tables = TRUE;
12INSERT INTO t1(a, b) VALUES
13('1001 MySQL Tricks','1. Never run mysqld as root. 2. q ...'),
14('MySQL vs. YourSQL use','In the following database comparison ...'),
15('MySQL Security','When run configured properly,MySQL ...');
16SELECT * FROM t1 WHERE (a, b) = ANY (SELECT a, MAX(b) FROM t1 GROUP BY a);
17a	b	c	d	e	f
181001 MySQL Tricks	1. Never run mysqld as root. 2. q ...	NULL	NULL	NULL	NULL
19MySQL vs. YourSQL use	In the following database comparison ...	NULL	NULL	NULL	NULL
20MySQL Security	When run configured properly,MySQL ...	NULL	NULL	NULL	NULL
21DROP TABLE t1;
22