I haven’t tested your code, just tried to help you understand how it operates in comment; WITH cteReports (EmpID, FirstName, LastName, MgrID, EmpLevel) AS ( –>>>>>>>>>>Block 1>>>>>>>>>>>>>>>>> — In a rCTE, this block is called an [Anchor] — The query finds all root nodes as described by WHERE ManagerID IS NULL SELECT EmployeeID, FirstName, LastName, … Read more
MySQL prior to version 8.0 doesn’t support the WITH clause (CTE in SQL Server parlance; Subquery Factoring in Oracle), so you are left with using: TEMPORARY tables DERIVED tables inline views (effectively what the WITH clause represents – they are interchangeable) The request for the feature dates back to 2006. As mentioned, you provided a … Read more
It depends. First of all What is a Common Table Expression? A (non recursive) CTE is treated very similarly to other constructs that can also be used as inline table expressions in SQL Server. Derived tables, Views, and inline table valued functions. Note that whilst BOL says that a CTE “can be thought of as … Read more
Per the other comments the second Common Table Expression [CTE] is preceded by a comma not a WITH statement so WITH cte1 AS (SELECT…) , cte2 AS (SELECT…) SELECT * FROM cte1 c1 INNER JOIN cte2 c2 ON …….. In terms of your actual query this syntax should work in PostgreSql, Oracle, and sql-server, well … Read more
Specify the maxrecursion option at the end of the query: … from EmployeeTree option (maxrecursion 0) That allows you to specify how often the CTE can recurse before generating an error. Maxrecursion 0 allows infinite recursion.
In the sub-query vs simple (non-recursive) CTE versions, they are probably very similar. You would have to use the profiler and actual execution plan to spot any differences, and that would be specific to your setup (so we can’t tell you the answer in full). In general; A CTE can be used recursively; a sub-query … Read more
You need to put the CTE first and then combine the INSERT INTO with your select statement. Also, the “AS” keyword following the CTE’s name is not optional: WITH tab AS ( bla bla ) INSERT INTO dbo.prf_BatchItemAdditionalAPartyNos ( BatchID, AccountNo, APartyNo, SourceRowID ) SELECT * FROM tab Please note that the code assumes that … Read more
While not strictly nested, you can use common table expressions to reuse previous queries in subsequent ones. To do this, the form of the statement you are looking for would be WITH x AS ( SELECT * FROM MyTable ), y AS ( SELECT * FROM x ) SELECT * FROM y
You can have multiple CTEs in one query, as well as reuse a CTE: WITH cte1 AS ( SELECT 1 AS id ), cte2 AS ( SELECT 2 AS id ) SELECT * FROM cte1 UNION ALL SELECT * FROM cte2 UNION ALL SELECT * FROM cte1 Note, however, that SQL Server may reevaluate the … Read more
Sample DDL create table #Temp ( EventID int, EventTitle Varchar(50), EventStartDate DateTime, EventEndDate DatetIme, EventEnumDays int, EventStartTime Datetime, EventEndTime DateTime, EventRecurring Bit, EventType int ) ;WITH Calendar AS (SELECT /*…*/) Insert Into #Temp Select EventID, EventStartDate, EventEndDate, PlannedDate as [EventDates], Cast(PlannedDate As datetime) AS DT, Cast(EventStartTime As time) AS ST,Cast(EventEndTime As time) AS ET, EventTitle … Read more