作者:葛孝杰 | 来源:互联网 | 2018-04-18 19:07
mysqlselect语句可以查询表中的一个或更多字段,同时select语句还可查询函数返回的结果,本文章向码农介绍mysqlselect语句中使用函数,需要的朋友可以参考一下。
实例如下:
创建数据表:
mysql> CREATE TABLE Employee(
-> id int,
-> first_name VARCHAR(15),
-> last_name VARCHAR(15)
-> );
Query OK, 0 rows affected (0.03 sec)
向表中插入数据:
mysql> insert into Employee(id,first_name, last_name)values (1,'Jason','Martin');
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name)values(2,'Alison','Mathews');
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name)values(3,'James','Smith');
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name)values(4,'Celia','Rice');
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name)values(5,'Robert','Black');
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name)values(6,'Linda', 'Green');
Query OK, 1 row affected (0.01 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name)values(7,'David','Larry');
Query OK, 1 row affected (0.02 sec)
mysql>
mysql> insert into Employee(id,first_name, last_name)values(8,'James','Cat');
Query OK, 1 row affected (0.00 sec)
select语句中使用函数
mysql> SELECT concat(First_Name, " ",Last_Name) AS Name FROM Employee;
+----------------+
| Name |
+----------------+
| Jason Martin |
| Alison Mathews |
| James Smith |
| Celia Rice |
| Robert Black |
| Linda Green |
| David Larry |
| James Cat |
+----------------+
8 rows in set (0.00 sec)