使用 MySQL 替换逗号分隔结果中的数字?
mysqlmysqli database更新于 2024/1/30 17:29:00
为此，请使用 CASE 语句和 FIND_IN_SET()。让我们首先创建一个表 −
mysql> create table DemoTable1629 -> ( -> Month varchar(100) -> ); Query OK, 0 rows affected (0.64 sec)
使用 insert 命令在表中插入一些记录。
mysql> insert into DemoTable1629 values('2,4,6');
Query OK, 1 row affected (0.16 sec)
mysql> insert into DemoTable1629 values('1,3,5,12');
Query OK, 1 row affected (0.13 sec)
mysql> insert into DemoTable1629 values('7,8,9,10');
Query OK, 1 row affected (0.15 sec)
使用 select 语句显示表中的所有记录 −
mysql> select * from DemoTable1629;
这将产生以下输出 −
+----------+ | Month | +----------+ | 2,4,6 | | 1,3,5,12 | | 7,8,9,10 | +----------+ 3 rows in set (0.00 sec)
以下是替换逗号分隔结果中的数字的查询 −
mysql> select trim(trailing ',' from concat( -> CASE WHEN FIND_IN_SET(1, Month) THEN 'January,' ELSE '' END, -> CASE WHEN FIND_IN_SET(2, Month) THEN 'Feburary,' ELSE '' END, -> CASE WHEN FIND_IN_SET(3, Month) THEN 'March,' ELSE '' END, -> CASE WHEN FIND_IN_SET(4, Month) THEN 'April,' ELSE '' END, -> CASE WHEN FIND_IN_SET(5, Month) THEN 'May,' ELSE '' END, -> CASE WHEN FIND_IN_SET(6, Month) THEN 'June,' ELSE '' END, -> CASE WHEN FIND_IN_SET(7, Month) THEN 'July,' ELSE '' END, -> CASE WHEN FIND_IN_SET(8, Month) THEN 'August,' ELSE '' END, -> CASE WHEN FIND_IN_SET(9, Month) THEN 'September,' ELSE '' END, -> CASE WHEN FIND_IN_SET(10,Month) THEN 'October,' ELSE '' END, -> CASE WHEN FIND_IN_SET(11,Month) THEN 'November,' ELSE '' END, -> CASE WHEN FIND_IN_SET(12,Month) THEN 'December,' ELSE '' END -> )) -> from DemoTable1629;
这将产生以下输出 −
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | trim(trailing ',' from concat( CASE WHEN FIND_IN_SET(1, Month) THEN 'January,' ELSE '' END, CASE WHEN FIND_IN_SET(2, Month) THEN 'Feburary,' ELSE '' END, CASE WHEN FIND_IN_SET(3, Month) THEN 'Marh,' ELSE '' END, CASE WHEN FIND_IN_SET(4, Mon | +------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | Feburary,April,June | | January,March,May,December | | July,August,September,October | +------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ 3 rows in set (0.04 sec)
