MySQL 查詢以在單行中返回所有專案
為此,請使用 GROUP_CONCAT()。我們首先建立一個表格 -
mysql> create table DemoTable1355 -> ( -> Location text -> ); Query OK, 0 rows affected (0.57 sec)
使用 insert 命令在表中插入一些記錄 -
mysql> insert into DemoTable1355 values('E:'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable1355 values('AllPrograms'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable1355 values('ChatApplicationInJava'); Query OK, 1 row affected (0.38 sec) mysql> insert into DemoTable1355 values('MainFolder'); Query OK, 1 row affected (0.23 sec)
使用 select 語句顯示錶中的所有記錄 -
mysql> select * from DemoTable1355;
這將產生以下輸出 -
+-----------------------+ | Location | +-----------------------+ | E: | | AllPrograms | | ChatApplicationInJava | | MainFolder | +-----------------------+ 4 rows in set (0.00 sec)
以下是返回一行中所有專案的查詢 -
mysql> select group_concat(Location separator '/') from DemoTable1355;
這將產生以下輸出 -
+-------------------------------------------------+ | group_concat(Location separator '/') | +-------------------------------------------------+ | E:/AllPrograms/ChatApplicationInJava/MainFolder | +-------------------------------------------------+ 1 row in set (0.00 sec)
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