Error Message:
Msg 253, Level 16, State 1, Line 1
Recursive member of a common table expression ‘%.*ls’ has multiple recursive references.
Severity level:
16.
Description:
This error message appears when the recursive part of a Common Table Expression has more than one recursive reference.
Consequences:
The T-SQL statement can be parsed, but causes the error at runtime.
Resolution:
Error of the Severity level 16 are generated by the user and can be fixed by the SQL Server user. The statement cannot be executed this way. Each CTE can have just one recursive reference.
Versions:
This error message was introduced with SQL Server 2005.
Example(s):
USE tempdb;
GO
IF OBJECT_ID(‘tempdb..#t’) > 0
DROP TABLE #t
GO
CREATE TABLE #t
(
id INT,
reportToID INT NULL,
)
INSERT INTO #t SELECT 1, NULL
UNION ALL SELECT 2, 1
UNION ALL SELECT 3, 1
UNION ALL SELECT 4, 2
GO
WITH MyCTE (id, reportToID, Level)
AS
(
SELECT t1.ID, t1.reportToID, 0 AS Level
FROM #t AS t1
WHERE reportToID IS NULL
UNION ALL
SELECT t1.ID, t1.reportToID, Level + 1
FROM #t AS t1
JOIN MyCTE AS t2
ON t1.reportToID = t2.ID
JOIN MyCTE AS t3
ON t1.reportToID = t3.ID
)
SELECT *
FROM MyCTE
GO
Remarks:
In the above example we try to reference the CTE more than once in the recursive part. This raises the error.