CODEWITHSUNDEEP
sqlsql-serverfunction
Serj Sagan
Serj Sagan

Reputation: 30218

Which is more correct with SQL Functions, Join or in Where clause?

I know that there are similar questions floating around (like SQL Filter criteria in join criteria or where clause which is more efficient) but as I remember SQL functions are special. Maybe? So basically which is more correct/more performant?

SELECT *
  FROM  [DBOne].[dbo].[SomeData] SD
    INNER JOIN [DBTwo].[DBOne].[SomeOtherData_GetALL]() SOD ON SD.[DataID] = SOD.[DataID]

OR

SELECT *
  FROM  [DBOne].[dbo].[SomeData] SD
  WHERE SD.[DataID] IN (SELECT [DataID] FROM [DBTwo].[DBOne].[SomeOtherData_GetALL]())

Upvotes: 0

Views: 85

Answers (2)

Steve Dowling
Steve Dowling

Reputation: 1999

I usually use WHERE EXISTS instead of joining. See here for an explanation.

Upvotes: 1

japzdivino
japzdivino

Reputation: 1746

Basically it is like asking JOIN vs SUB QUERY, if you are concern with the performance, i suggest to use the JOIN instead of using WHERE IN clause, you can see the difference of the performance if you use the execution plan of SQL.

To further understand, you can read this post: Join vs. sub-query

Hope this help.

Upvotes: 0

Related Questions