移除 column record 中除了最后 7 个字符之外的所有内容的 MySQL 查询


我们首先创建一个表 −

mysql> create table DemoTable
(
   Strength text
);
Query OK, 0 rows affected (0.51 sec)

使用 insert 命令在表中插入一些记录 −

mysql> insert into DemoTable values('John is a good programmer');
Query OK, 1 row affected (0.09 sec)
mysql> insert into DemoTable values('Chris is a good player in cricket');
Query OK, 1 row affected (0.12 sec)
mysql> insert into DemoTable values('Bob is good in algorithm');
Query OK, 1 row affected (0.42 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 −

+-----------------------------------+
| Strength                          |
+-----------------------------------+
| John is a good programmer         |
| Chris is a good player in cricket |
| Bob is good in algorithm          |
+-----------------------------------+
3 rows in set (0.00 sec)

以下是移除 column record 中除了最后 7 个字符之外的所有内容的查询 −

mysql> update DemoTable set Strength=substr(Strength,-7,7);
Query OK, 3 rows affected (0.46 sec)
Rows matched: 3 Changed: 3 Warnings: 0

让我们再次检查表记录 −

mysql> select *from DemoTable;

这将产生以下输出 −

+----------+
| Strength |
+----------+
| grammer  |
| cricket  |
| gorithm  |
+----------+
3 rows in set (0.00 sec)

更新日期: 2019-09-26

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