大家好，又见面了，我是你们的朋友全栈君。
您可以使用SUBSTRING()MySQL来限制字符串的长度。语法如下SELECT SUBSTRING(yourColumnName,1,yourIntegerValueToGetTheCharacters) as
anyVariableName from yourTableName;
为了理解上述语法，让我们创建一个表。创建表的查询如下mysql> create table limitLengthOfLongTextDemo
-> (
-> sentence LONGTEXT
-> );
使用insert命令在表中插入一些记录。查询如下mysql> insert into limitLengthOfLongTextDemo values(‘This is the introduction to MySQL’);
mysql> insert into limitLengthOfLongTextDemo values(‘PL/SQL is the extension of Structured
Query Language’);
mysql> insert into limitLengthOfLongTextDemo values(‘Java is an Object Oriented
Programming Language’);
使用select语句显示表中的所有记录。查询如下mysql> select *from limitLengthOfLongTextDemo;
以下是输出+——————————————————+
| sentence |
+——————————————————+
| This is the introduction to MySQL |
| PL/SQL is the extension of Structured Query Language |
| Java is an Object Oriented Programming Language |
+——————————————————+
3 rows in set (0.00 sec)
这是获取给定值字符的查询mysql> select substring(sentence,1,26) as 26Characters from limitLengthOfLongTextDemo;
以下是输出+—————————-+
| 26Characters |
+—————————-+
| This is the introduction t |
| PL/SQL is the extension of |
| Java is an Object Oriented |
+—————————-+
3 rows in set (0.00 sec)
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