MySQL 如何使用MySQL TRIM()从所有行中删除空格并更新表格?
假设表格中的许多值在表格的列中都有空格,那么这是一种浪费空间的情况。我们可以使用TRIM()函数从所有行中删除空格,并在单个查询中更新表格。以下来自具有所有行中空格的“Employee”的示例将展示该概念−
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示例
mysql> Select * from Employee;
+------+----------------------+----------------------+----------------------+
| Id | Name | Address | Department |
+------+----------------------+----------------------+----------------------+
| 100 | Raman | Delhi | IT |
| 101 | Mohan | Haryana | History |
| 102 | Shyam | Chandigarh | ENGLISH |
| 103 | Sukhjeet Singh | Patiala | Computer Engg. |
| 104 | Bimal Roy | Calcutta | Computer Engg. |
+------+----------------------+----------------------+----------------------+
5 rows in set (0.00 sec)
我们可以从上面的结果集中看到,Employee表中的行有很多空格。可以使用以下查询删除并更新它们−
mysql> Update Employee SET Id = TRIM(Id), Name = TRIM(Name), Address = TRIM(Address), DEPARTMENT = TRIM(Department);
Query OK, 5 rows affected (0.24 sec)
Rows matched: 5 Changed: 5 Warnings: 0
mysql> Select * from Employee;
+------+----------------+------------+----------------+
| Id | Name | Address | Department |
+------+----------------+------------+----------------+
| 100 | Raman | Delhi | IT |
| 101 | Mohan | Haryana | History |
| 102 | Shyam | Chandigarh | ENGLISH |
| 103 | Sukhjeet Singh | Patiala | Computer Engg. |
| 104 | Bimal Roy | Calcutta | Computer Engg. |
+------+----------------+------------+----------------+
5 rows in set (0.00 sec)
我们可以从上面的结果集中看到,所有空格已被删除且表格已更新。