mysql longtext 超时_限制MySQL SELECT结果中longtext字段的长度？

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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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