使用 MySQL 按特定顺序获取记录?
mysqlmysqli database
您可以使用 ORDER BY IF() 按特定顺序获取记录。让我们首先创建一个表:
mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, FirstName varchar(20), Branch varchar(20) ); Query OK, 0 rows affected (1.96 sec)
下面是使用 insert 命令在表中插入一些记录的查询:
mysql> insert into DemoTable(FirstName,Branch) values('John','CS');
Query OK, 1 row affected (0.22 sec)
mysql> insert into DemoTable(FirstName,Branch) values('Carol','ME');
Query OK, 1 row affected (0.25 sec)
mysql> insert into DemoTable(FirstName,Branch) values('David','ME');
Query OK, 1 row affected (0.11 sec)
mysql> insert into DemoTable(FirstName,Branch) values('Bob','CE');
Query OK, 1 row affected (0.35 sec)
mysql> insert into DemoTable(FirstName,Branch) values('Robert','EE');
Query OK, 1 row affected (0.19 sec)
mysql> insert into DemoTable(FirstName,Branch) values('Chris','EEE');
Query OK, 1 row affected (0.27 sec)
mysql> insert into DemoTable(FirstName,Branch) values('James','ME');
Query OK, 1 row affected (0.56 sec)
以下是使用 select 命令显示表中记录的查询:
mysql> select *from DemoTable;
这将产生以下输出:
+----+-----------+--------+ | Id | FirstName | Branch | +----+-----------+--------+ | 1 | John | CS | | 2 | Carol | ME | | 3 | David | ME | | 4 | Bob | CE | | 5 | Robert | EE | | 6 | Chris | EEE | | 7 | James | ME | +----+-----------+--------+ 7 rows in set (0.00 sec)
以下是使用 MySQL 按特定顺序获取记录的查询。我们设置的顺序从分支"ME"开始:
mysql> select *from DemoTable order by if(Branch='ME',1,0)DESC,Branch;
这将产生以下输出:
+----+-----------+--------+ | Id | FirstName | Branch | +----+-----------+--------+ | 2 | Carol | ME | | 3 | David | ME | | 7 | James | ME | | 4 | Bob | CE | | 1 | John | CS | | 5 | Robert | EE | | 6 | Chris | EEE | +----+-----------+--------+ 7 rows in set (0.00 sec)
