在MySQL的SELECT语句中使用通配符？

如果要添加通配符，可以使用concat()的概念。其语法如下 –

select *from yourTableName where yourColumnName like concat('%',yourValue,'%');

让我们创建一个表 –

mysql> create table demo48
-> (
−> id int not null auto_increment primary key,
−> name varchar(20)
−> );
Query OK, 0 rows affected (0.70 sec)

使用insert命令将一些记录插入表中 –

mysql> insert into demo48(name) values('John Smith');
Query OK, 1 row affected (0.12 sec)

mysql> insert into demo48(name) values('John Doe');
Query OK, 1 row affected (0.12 sec)

mysql> insert into demo48(name) values('Adam Smith');
Query OK, 1 row affected (0.23 sec)

mysql> insert into demo48(name) values('David Miller');
Query OK, 1 row affected (0.14 sec)

mysql> insert into demo48(name) values('Chris Brown');
Query OK, 1 row affected (0.11 sec)

使用SELECT语句从表中显示记录 –

mysql> select *from demo48;

这将产生以下输出 –

+----+--------------+
| id | name         |
+----+--------------+
|  1 | John Smith   |
|  2 | John Doe     |
|  3 | Adam Smith   |
|  4 | David Miller |
|  5 | Chris Brown  |
+----+--------------+
5 rows in set (0.00 sec)

下面是在SELECT语句中添加通配符的查询语句 –

mysql> select *from demo48 where name like concat('%','Smith','%');

这将产生以下输出 –

+----+------------+
| id | name       |
+----+------------+
|  1 | John Smith |
|  3 | Adam Smith |
+----+------------+
2 rows in set (0.00 sec)

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