sql - 将四个表列限制为 Firebird DBMS 中的不同值

Question

我有一个包含 4 个唯一列的表

我试过这样的东西:

ALTER TABLE "FolderDsg" ADD CONSTRAINT CHK4_FOLDERDSG CHECK (ORDER2 = ORDER3) 
ALTER TABLE "FolderDsg" ADD CONSTRAINT CHK11_FOLDERDSG CHECK (ORDER1 not in (ORDER2)) 
ALTER TABLE "FolderDsg" ADD CONSTRAINT CHK13_FOLDERDSG CHECK (ORDER1 like (ORDER2)) 
/******************************************************************************/ 
/*                             Unique Constraints                             */ 
/******************************************************************************/ 
ALTER TABLE "FolderDsg" ADD CONSTRAINT UNQ1_FOLDERDSG UNIQUE (ORDER1) 
USING INDEX "_IDXORDER1" 

它适用于每一列。但是我怎样才能为所有 4 列创建一个唯一的呢？

+------+------+------+------+
|Order1|Order2|Order3|Order4| 
+------+------+------+------+
|1     |2     |3     |4     | = valid OK Check
+------+------+------+------+
|5     |5     |6     |7     | = not valid ( That works in the Database ) 
+------+------+------+------+
|8     |9     |10    |11    | = valid OK Check 
+------+------+------+------+
|12    |13    |9     |14    | = valid  ( That's the Problem ) I need a not valid 
+------+------+------+------+

Answer 1

你试过吗？

ALTER TABLE "FolderDsg" ADD CONSTRAINT CHECK (ORDER1 not in (ORDER2, ORDER3, ORDER4) and
                                              ORDER2 not in (ORDER3, ORDER4) and
                                              ORDER3 not in (ORDER4)
                                             );

编辑:

如果您还希望列中的值是唯一的，您可以添加四个唯一约束:

ALTER TABLE "FolderDsg" ADD CONSTRAINT UNIQUE (ORDER1);
ALTER TABLE "FolderDsg" ADD CONSTRAINT UNIQUE (ORDER2);
ALTER TABLE "FolderDsg" ADD CONSTRAINT UNIQUE (ORDER3);
ALTER TABLE "FolderDsg" ADD CONSTRAINT UNIQUE (ORDER4);

编辑二；

而且，如果您真的希望所有列中的所有值都不同，您有两种选择。第一种是使用 before update/before insert 触发器。第二种更可取:以规范化格式存储数据。

创建一个表，每个“FolderDsg”和订单各占一行:

create table FolderDsgOrder (
    FolderDsgId int,
    OrderNum int,
    OrderValue int
    /* whatever else you want goes here */
);

现在您可以创建简单的约束:

alter table FolderDsgOrder add constraint unique (OrderValue);