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Legal StudiesMySQL query 可以在列中用目錄連結替換最後一個“/”之後的字串嗎？
為此，請使用 substring_index() 方法。我們首先建立一個表格：
mysql> create table DemoTable -> ( -> FolderName varchar(100), -> FolderLocation varchar(200) -> ); Query OK, 0 rows affected (1.03 sec)
使用 insert 命令在表格中插入一些記錄：
mysql> insert into DemoTable values('CProgram','C:/AllPrograms/.....');
Query OK, 1 row affected (0.13 sec)
mysql> insert into DemoTable values('Images','E:/MyImage/home/garbage');
Query OK, 1 row affected (0.15 sec)使用 select 語句顯示錶格中的所有記錄：
mysql> select *from DemoTable;
輸出
+------------+-------------------------+ | FolderName | FolderLocation | +------------+-------------------------+ | CProgram | C:/AllPrograms/..... | | Images | E:/MyImage/home/garbage | +------------+-------------------------+ 2 rows in set (0.00 sec)
以下是用目錄連結替換列中最後一個“/”之後的字串的查詢：
mysql> UPDATE DemoTable SET FolderLocation = CONCAT(LEFT(FolderLocation , CHAR_LENGTH(FolderLocation ) - CHAR_LENGTH(SUBSTRING_INDEX(FolderLocation , '/', -1))),FolderName); Query OK, 2 rows affected (0.16 sec) Rows matched: 2 Changed: 2 Warnings: 0
讓我們再次查看錶格記錄：
mysql> select *from DemoTable;
輸出
+------------+-------------------------+ | FolderName | FolderLocation | +------------+-------------------------+ | CProgram | C:/AllPrograms/CProgram | | Images | E:/MyImage/home/Images | +------------+-------------------------+ 2 rows in set (0.00 sec)
更新於： 30-Jul-2019
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