1.sqlserver
使用 + 运算符进行连接操作
select ename + 'work as a' + job as msg from emp where deptno=10
2.DB2,Oracle,PostgreSQL
使用双竖线作为连接运算符
select * ename || 'work as a' || job as msg from emp where deptno=10
3.mySQL
支出contact函数
select contact(ename, 'work as',job)as msg from emp where deptno=10