field
field
description
Syntax
field(Expr e, param1, param2, param3,.....)
In the order by clause, you can use custom sorting to arrange the data in expr in the specified param1, 2, and 3 order. The data not in the param parameter will not participate in sorting, but will be placed first. You can use asc and desc to control the overall order. If there is a NULL value, you can use nulls first, nulls last to control the order of nulls.
example
mysql> select k1,k7 from baseall where k1 in (1,2,3) order by field(k1,2,1,3);
+------+------------+
| k1 | k7 |
+------+------------+
| 2 | wangyu14 |
| 1 | wangjing04 |
| 3 | yuanyuan06 |
+------+------------+
mysql> select class_name from class_test order by field(class_name,'Suzi','Ben','Henry');
+------------+
| class_name |
+------------+
| Suzi |
| Suzi |
| Ben |
| Ben |
| Henry |
| Henry |
+------------+
mysql> select class_name from class_test order by field(class_name,'Suzi','Ben','Henry') desc;
+------------+
| class_name |
+------------+
| Henry |
| Henry |
| Ben |
| Ben |
| Suzi |
| Suzi |
+------------+
mysql> select class_name from class_test order by field(class_name,'Suzi','Ben','Henry') nulls first;
+------------+
| class_name |
+------------+
| null |
| Suzi |
| Suzi |
| Ben |
| Ben |
| Henry |
| Henry |
+------------+keywords
field