OracleSQL> SELECT2 CONCAT('Good ', 'Morning!') A,3 'Good ' || 'Morning!' B4 FROM5 dual;A B-------------------------- --------------------------Good Morning! Good Morning!SQL Server1> SELECT 'Good ' + 'Morning!' B2> goB-------------Good Morning!(1 行受影响)MySQLmysql> select CONCAT('Good ', 'Morning!') A-> //+---------------+| A |+---------------+| Good Morning! |+---------------+1 row in set (0.02 sec)
1、SELECT A+B FROM TABLE2、如果是布尔值:SELECT A & B FROM TABLE