Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
461 views
in Technique[技术] by (71.8m points)

sql server - ALTER TABLE my_table ADD @column INT

If i want to use a variable as name of the new column, is this posible in MS SQL?

Example that dont work:

ALTER TABLE my_table ADD @column INT

This worked great for me:

EXEC ('ALTER TABLE my_table ADD ' + @column + ' INT')
See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

This is possible using dynamic sql to build your DDL and using the EXEC command to execute the string.

Declare @SQL VarChar(1000)

SELECT @SQL = 'ALTER TABLE my_table ADD ' + @column + ' INT'

Exec (@SQL)

See this article.

I will also add that the moment you venture to the land of dynamic sql, you need to take care to not expose yourself to SQL Injection attacks. Always clean up the parameters coming in.

As Philip mentions - think long and hard before doing this. The fact that it is possible does not make it a good thing...

Erland Sommarskog wrote an extensive article about using dynamic sql - The curse and blessings of dynamic SQL which I recommend reading fully.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

1.4m articles

1.4m replys

5 comments

57.0k users

...