如何在MySQL中仅显示总值中的200个字符?

您可以使用LEFT()MySQL来显示MySQL整个值中的某些字符。以下是语法:

select left(yourColumnName ,200 ) AS anyAliasName from yourTableName;

让我们首先创建一个表:

mysql> create table DemoTable (Paragraph longtext);

以下是使用insert命令在表中插入记录的查询:

mysql> insert into DemoTable values('Introduction to Java,Introduction to C,Introduction to
C++,Introduction to Spring,Introduction to Hibernate,Introduction to Python,Introduction to
MySQL,Introduction to MongoDB,Introduction to SQL Server,Introduction to
ASP.net,Introduction to JSF');

以下是使用select命令显示表中记录的查询:

mysql> select *from DemoTable;

这将产生以下输出:

+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Paragraph                                                                                                                                                                                                                                                               |
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Introduction to Java,Introduction to C,Introduction to C++,Introduction to Spring,Introduction to Hibernate,Introduction to Python,Introduction to MySQL,Introduction to MongoDB,Introduction to SQL Server,Introduction to ASP.net,Introduction to JSF                |
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

以下是查询,仅显示总值中的200个字符:

mysql> select left(Paragraph ,200) AS `200Characters` from DemoTable;

这将产生以下输出,仅显示前200个字符:

+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| 200Characters                                                                                                                                                                                                                         |
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Introduction to Java,Introduction to C,Introduction to C++,Introduction to Spring,Introduction to Hibernate,Introduction to Python,Introduction to MySQL,Introduction to MongoDB,Introduction to SQL Ser                                                                                                                                                                                                        |
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)