MySQL 中字段的 Substring()?
mysqlmysqli database
您可以使用 MySQL 中字段的 substring() 来获取字符串的一部分。以下是语法 −
select substring(yourColumnName,yourStartingIndex,yourEndingIndex) from yourTableName;
首先我们创建一个表 −
mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Title longtext ); Query OK, 0 rows affected (0.57 sec)
使用 insert 命令在表中插入一些记录 −
mysql> insert into DemoTable(Title) values('MySQL is a relational database management system');
Query OK, 1 row affected (0.12 sec)
mysql> insert into DemoTable(Title) values('MongoDB is a popular No SQL database');
Query OK, 1 row affected (0.18 sec)
使用 select 语句显示表中的所有记录 −
mysql> select *from DemoTable;
这将产生以下输出 −
+----+--------------------------------------------------+ | Id | Title | +----+--------------------------------------------------+ | 1 | MySQL is a relational database management system | | 2 | MongoDB is a popular No SQL database | +----+--------------------------------------------------+ 2 rows in set (0.00 sec)
以下是使用 substring() 对字段进行的查询。
mysql> select substring(Title,1,21) from DemoTable;
这将产生以下输出 −
+-----------------------+ | substring(Title,1,21) | +-----------------------+ | MySQL is a relational | | MongoDB is a popular | +-----------------------+ 2 rows in set (0.00 sec)
