BUG: MERGE statement not parsing correctly with target alias

[SGStino]

This fails to parse:

MERGE [testDb].[dbo].[testTbl] AS [target]
USING (VALUES (@key1, @key2, @key1, @key2 ))
  AS [source] ([key1], [key2], [key1], [key2])
 ON [key1] = @key1 AND [key2] = @key2
WHEN MATCHED THEN
  UPDATE SET [source].[data1] = [target].[data1] , [source].[data2] = [target].[data2]
WHEN NOT MATCHED BY TARGET
  THEN INSERT ([key1], [key2], [data1], [data2]) VALUES ([source].[key1], [source].[key2], [source].[data1], [source].[data2]);

while

MERGE [testDb].[dbo].[testTbl] [target]
USING (VALUES (@key1, @key2, @key1, @key2 ))
  AS [source] ([key1], [key2], [key1], [key2])
 ON [key1] = @key1 AND [key2] = @key2
WHEN MATCHED THEN
  UPDATE SET [source].[data1] = [target].[data1] , [source].[data2] = [target].[data2]
WHEN NOT MATCHED BY TARGET
  THEN INSERT ([key1], [key2], [data1], [data2]) VALUES ([source].[key1], [source].[key2], [source].[data1], [source].[data2]);

parses correctly.

I'm assuming that the AS isn't expected after the column name of the MERGE while it should be?

[bruce-dunwiddie]

Thank you for reporting the issue.

I'll look into it.

[SGStino]

It seems like there are more edge cases in the parsing of a MERGE:

MERGE [testDb]. [dbo]. [testTbl] [target]
USING ( VALUES ( @key1, @key2, @data1, @data2 ))
    AS [source] ( [key1], [key2], [data1], [data2])
  ON [target]. [key1] = [source]. [key1] ,  [target]. [key2] = [source]. [key2]
WHEN MATCHED THEN
    UPDATE SET [target]. [data1] = [source]. [data1] ,  [target]. [data2] = [source]. [data2]
WHEN NOT MATCHED BY TARGET
    THEN INSERT ( [key1], [key2], [data1], [data2]) VALUES ( [source]. [key1], [source]. [key2], [source]. [data1], [source]. [data2]) OUTPUT cast(1 as bit) AS RowExists, 1 as RowsUpdatedOrInserted, @@ERROR as ErrorCode, [INSERTED]. [key1], [INSERTED]. [key2], [INSERTED]. [data1], [INSERTED]. [data2];

It doesn't seem to like the CAST(1 as bit) AS RowExists, but here it doesn't even parse the implicit alias syntax, so even 1 RowExists doesn't get parsed correctly here.

It just outputs a merge expression and an unknown expression, with CAST being the first token of the unknown expression.

[bruce-dunwiddie]

ok, I'll add this to the tests also.