CODEWITHSUNDEEP
sqlsql-servert-sqlouter-join
Arthur
Arthur

Reputation: 3473

What does the old-style JOIN syntax mean in T-SQL?

I need to edit old-styled T-SQL code.

I think, that they are JOIN, but I don't know, what JOIN type is each of them.

Upvotes: 4

Views: 4016

Answers (1)

Arthur
Arthur

Reputation: 3473

I found answer!

-- Example 1: Deprecated syntax for an inner join
SELECT [T2].[c3], [T1].[c3] 
FROM [dbo].[Table2] T2, [dbo].[Table1] T1 
WHERE [T1].[ID] = [T2].[ID]

-- Example 2: Current syntax for an inner join
SELECT [T2].[c3], [T1].[c3] 
FROM [dbo].[Table2] AS T2
INNER JOIN [dbo].[Table1] as T1
ON [T2].[ID] = [T1].[ID]

-- Example 3: Deprecated syntax for a left outer join
SELECT [T2].[c3], [T1].[c3] 
FROM [dbo].[Table2] T2, [dbo].[Table1] T1 
WHERE [T1].[ID] *= [T2].[ID]

-- Example 4: Fixed syntax for a left outer join
SELECT [T2].[c3], [T1].[c3] 
FROM [dbo].[Table2] AS T2
LEFT OUTER JOIN [dbo].[Table1] as T1
ON [T2].[ID] = [T2].[ID]

-- Example 5: Deprecated syntax for a right outer join
SELECT [T2].[c3], [T1].[c3] 
FROM [dbo].[Table2] T2, [dbo].[Table1] T1 
WHERE [T1].[ID] =* [T2].[ID]

-- Example 6: Fixed syntax for a right outer join
SELECT [T2].[c3], [T1].[c3] 
FROM [dbo].[Table2] AS T2
RIGHT OUTER JOIN [dbo].[Table1] as T1
ON [T2].[ID] = [T2].[ID]

https://msdn.microsoft.com/en-us/library/dd172122(v=vs.100).aspx

Upvotes: 5

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