Foreign key relationship with composite primary keys in SQL Server 2005

Since Table2 has a composite primary key (FileID, FileType), then any reference to it must also include both columns.

ALTER TABLE dbo.Table1
  FOREIGN KEY(FileID, FileType) REFERENCES Table2(FileID, FileType)

Unless you have a unique constraint/index on the Table2.FileID field (but if so: why isn’t this the PK??), you cannot create a FK relationship to only parts of the PK on the target table – just can’t do it.

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