MySQL 如何从文件位置记录表中获取子字符串结果

为了获取子字符串，请在MySQL中使用substr()方法，如下所示的语法 –

select substr(yourColumnName,startIndex,endIndex) from yourTableName limit anyValue;
select substr(yourColumnName,startIndex+endIndex) from yourTableName limit anyValue;

让我们创建一个表 –

mysql> create table demo11
−> (
−> id int NOT NULL AUTO_INCREMENT PRIMARY KEY,
−> fileLocation text
−> );
Query OK, 0 rows affected (2.60 sec)

使用insert命令将一些记录插入表中 –

mysql> insert into demo11(fileLocation) values('E:/users/program/sample.sql');
Query OK, 1 row affected (0.15 sec)

mysql> insert into demo11(fileLocation) values('E:/users/data/db.sql');
Query OK, 1 row affected (0.32 sec)

mysql> insert into demo11(fileLocation) values('C:/users/data/sample2.sql');
Query OK, 1 row affected (0.13 sec)

使用select语句从表中显示记录 –

mysql> select *from demo11;

这将产生以下输出 –

+----+-----------------------------+
| id | fileLocation                |
+----+-----------------------------+
|  1 | E:/users/program/sample.sql |
|  2 | E:/users/data/db.sql        |
|  3 | C:/users/data/sample2.sql   |
+----+-----------------------------+
3 rows in set (0.00 sec)s

以下是在多行中获取子字符串结果的查询。

第一部分查询如下 –

mysql> select substr(fileLocation,1,15) from demo11 limit 1,2;

这将产生以下输出 –

+---------------------------+
| substr(fileLocation,1,15) |
+---------------------------+
| E:/users/data/d           |
| C:/users/data/s           |
+---------------------------+
2 rows in set (0.00 sec)

第二部分如下 –

mysql> select substr(fileLocation,16) from demo11 limit 1,2;

这将产生以下输出 –

+-------------------------+
| substr(fileLocation,16) |
+-------------------------+
| b.sql                   |
| ample2.sql              |
+-------------------------+
2 rows in set (0.00 sec)

阅读更多：MySQL 教程