SQL 使用现有主键在 DB2 中添加现有列作为主键
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/15152159/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Adding existing column as primary key in DB2 with existing primary keys
提问by Vicky
I have a table MY_TABLE in DB2 containing several columns:
我在 DB2 中有一个表 MY_TABLE 包含几列：
PRODUCT_ID
ADDED_DT
PRODUCT_NAME
PRODUCT_COLOR
PRODUCT_PRICE
EXPIRY_DT
Out of these columns, below columns form the primary key:
在这些列中，下面的列构成主键：
PRODUCT_ID
ADDED_DT
I want to add EXPIRY_DT as primary key such that the table will now have three primary keys viz. PRODUCT_ID, ADDED_DT and EXPIRY_DT
我想添加 EXPIRY_DT 作为主键，这样表现在将有三个主键，即。PRODUCT_ID、ADDED_DT 和 EXPIRY_DT
I tried below set of commands:
我尝试了以下命令集：
ALTER TABLE MY_TABLE ADD PRIMARY KEY (EXPIRY_DT);
REORG TABLE MY_TABLE;
However, the query failed with error:
但是，查询失败并出现错误：
Table "MY_TABLE" already has a "PRIMARY" key.
How to acheive this ?
如何实现这一目标？
回答by andy
First you need to drop the existing primary key and then add new primary key
首先你需要删除现有的主键，然后添加新的主键
ALTER TABLE Table_Name DROP PRIMARY KEY;
ALTER TABLE Table_Name ADD PRIMARY KEY (Column_One, Column_Two);
