用一个表更新另一个表
UPDATE table1 t1, table2 t2 SET t1.field1 = t2.field1, t1.field2 = t2.field2 WHERE t1.field3 = t2.field3;
UPDATE table1, table2 SET table1.field1 = table2.field1 WHERE table1.field2 = table2.field2;
用一个表更新另一个表
UPDATE table1 t1, table2 t2 SET t1.field1 = t2.field1, t1.field2 = t2.field2 WHERE t1.field3 = t2.field3;
UPDATE table1, table2 SET table1.field1 = table2.field1 WHERE table1.field2 = table2.field2;