SQL join different tables depending on row information

Posted by Xster on Stack Overflow See other posts from Stack Overflow or by Xster
Published on 2010-03-13T23:17:55Z Indexed on 2010/03/13 23:25 UTC
Read the original article Hit count: 301

Filed under:

sql

|

join

|

select

Hi, I think this question hasn't be asked yet.

Suppose I have table A with a field that can be either 1 or 2 How do I select such that for each row in table A, if the field is 1, join the select with table B and if the field is 2, join the select with table C?

© Stack Overflow or respective owner

Related posts about sql

SQL SERVER – Concat Strings in SQL Server using T-SQL – SQL in Sixty Seconds #035 – Video

as seen on SQL Authority - Search for 'SQL Authority'
Concatenating string is one of the most common tasks in SQL Server and every developer has to come across it. We have to concat the string when we have to see the display full name of the person by first name and last name. In this video we will see various methods to concatenate the strings. SQL… >>> More
SQL SERVER – Concat Function in SQL Server – SQL Concatenation

as seen on SQL Authority - Search for 'SQL Authority'
Earlier this week, I was delivering Advanced BI training on the subject of “SQL Server 2008 R2″. I had great time delivering the session. During the session, we talked about SQL Server 2010 Denali. Suddenly one of the attendees suggested his displeasure for the product. He said, even though… >>> More
Error with SQL Server Setup 2012 on Windows 2012

as seen on Server Fault - Search for 'Server Fault'
I am trying to install SQL Server on Windows 2012. I was able to finally get the wizard up and running after making some changes on the server, but now it fails no matter what I do with the following error: TITLE: SQL Server Setup failure. SQL Server Setup has encountered the following error: … >>> More
How can I detect which version of SQL (eg SQL 2008 or SQL Azure)

as seen on Stack Overflow - Search for 'Stack Overflow'
I need to detect which version of SQL I am dealing with to perorm various tasks, I need specifically detect if I am on SQL 2008 or SQL Azure. How can I do this with detection code written in SQL? >>> More
Nested SQL Select statement fails on SQL Server 2000, ok on SQL Server 2005

as seen on Stack Overflow - Search for 'Stack Overflow'
Here is the query: INSERT INTO @TempTable SELECT UserID, Name, Address1 = (SELECT TOP 1 [Address] FROM (SELECT TOP 1 [Address] FROM [UserAddress] ua INNER JOIN UserAddressOrder uo ON ua.UserID = uo.UserID WHERE ua.UserID = u.UserID ORDER BY uo.AddressOrder ASC) q ORDER BY AddressOrder… >>> More

Related posts about join

Improving Partitioned Table Join Performance

as seen on SQL Blog - Search for 'SQL Blog'
The query optimizer does not always choose an optimal strategy when joining partitioned tables. This post looks at an example, showing how a manual rewrite of the query can almost double performance, while reducing the memory grant to almost nothing. Test Data The two tables in this example use… >>> More
MS SQL 2008, join or no join?

as seen on Stack Overflow - Search for 'Stack Overflow'
Just a small question regarding joins. I have a table with around 30 fields and i was thinking about making a second table to store 10 of those fields. Then i would just join them in with the main data. The 10 fields that i was planning to store in a second table does not get queried directly, it's… >>> More
SQL Server 2008, join or no join?

as seen on Stack Overflow - Search for 'Stack Overflow'
Just a small question regarding joins. I have a table with around 30 fields and i was thinking about making a second table to store 10 of those fields. Then i would just join them in with the main data. The 10 fields that i was planning to store in a second table does not get queried directly, it's… >>> More
Simple join gives unnecessary rows,How to get join properly with only matches in both tables

as seen on Stack Overflow - Search for 'Stack Overflow'
Table 1 Field1 Field2 AA 20 AA 20 AB 12 AC 13 Table2 field3 field4 AA 20 AA 20 AC 13 AD 23 AW 21 output required: newfield field2 field4 AA 20 20 AA 20 20 AC 13 13 I used: select field1 as newfield, t1.field2,t2.field4 from table1 t1 join table2 t2 on t1.field1=t2.field3 This… >>> More
Mulitple full joins in Postgres is slow

as seen on Stack Overflow - Search for 'Stack Overflow'
I have a program to use the IMDB database and am having very slow performance on my query. It appears that it doesn't use my where condition until after it materializes everything. I looked around for hints to use but nothing seems to work. Here is my query: SELECT * FROM name as n1 FULL JOIN… >>> More