Re But WHYMust That Column Be Contained in an Aggregate Function or the GROUP BY clause Im with Kevin. If Im joining to a table based on its primary key, then. Possibly, all fields are added to WHERE clause of update statement because your table has no primary key. To see the update statement that is executed when you modify. Session ID Status Title Type Day Start Time End Time Abstract Presenter1 Full Name Presenter1 Company CoPresenter1 Full Name CoPresenter1 Company Presenter2 Full Name. How to remove empty rows from Data. Table. Each month, over 5. Stack Overflow to learn, share their knowledge, and build their careers. Join the worlds largest developer community. Using Table Valued Parameters in SQL Server and. NETAn SQL text by Erland Sommarskog, SQL Server MVP. Latest. revision 2. Copyright applies to this text. See here for font conventions used in this article. Introduction. This is an article that is intended to get you started with passing table valued parameters TVPs to SQL Server from. NET. I begin with presenting how you use table valued parameters in SQL Server itself whereupon I give a quick overview of the mechanisms to pass TVPs from ADO. NET to SQL Server. The main meat of this article are two real world examples where I use TVPs. The first example is the classical problem of passing a comma separated list of values to SQL Server, this time through a table valued parameter. You will be amazed of how simple it is. In the second example I show two ways to load a file with master detail data into tables in SQL Server. In addition to the examples, there is also some discussion on how you can improve performance when loading large amounts of data. Despite the appearance of. NET in the title of this article, there is a final chapter that explores the possibilities in other APIs, of which some support TVPs and some do not. This includes Entity Framework which has no support for TVPs. In this chapter I briefly discuss workarounds when TVPs are not available to you. Some of the sample code in this article refers to the Northwind database. This database does not ship with SQL Server, but you can download the script to. Microsofts web site. Note This article was originally published as Arrays and Lists in SQL Server 2. Arrays and Lists article. I have since renamed it, so that the title better reflects the contents. Table Valued Parameters in TSQLDeclarations. Lets first look at how to use TVPs in TSQL without involving a client. To be able to declare a TVP, you first need. CREATE TYPE integerlisttbltype AS TABLE n int NOT NULL PRIMARY KEYThat is, after CREATE TYPE you specify the type name followed by AS TABLE and then. CREATE TABLE. You cannot use everything you can use with CREATE. TABLE, but you can define PRIMARY KEY, UNIQUE and CHECK constraints, you can use IDENTITY and DEFAULT definitions. Starting with SQL 2. For instance CREATE TYPE tabletype AS TABLE a int NOT NULL PRIMARY KEY. NOT NULL. c int NOT NULL. INDEX ix b,c WHERE b 2. Although, this particular example only runs on SQL 2. SQL 2. 01. 4 you cannot have filtered indexes in a table type. While it is nothing we will explore in this article, it is worth noting that you can use table types with In Memory OLTP, in which case you add the MEMORYOPTIMIZED clause to the type definition CREATE TYPE hekatontype AS TABLEa int NOT NULL PRIMARY KEY NONCLUSTERED. WITH MEMORYOPTIMIZED ONThis requires SQL 2. Once you have this table type, you can use it. DECLARE mylist integerlisttbltype. However, you cannot use the type with CREATE TABLE it could have been nutty with temp tables, nor can you use it for. The raison dtre for table types is to make it possible to declare table valued parameters for stored procedures or user defined functions. Here is one example CREATE PROCEDURE getproductnames prodids integerlisttbltype READONLY AS. SELECT p. Product. ID, p. Product. Name. FROM Northwind. dbo. Products p. WHERE p. Product. ID IN SELECT n FROM prodidsThe body of the procedure brings no surprises. The code looks just as it would have if prodids had been a local. The parameter declaration on the other hand includes a keyword hitherto not seen in this. READONLY. This keyword means what it says you cannot modify the contents of the table parameter in any. As an aside, this restriction makes TVPs far less useful than they could have been. I discuss in my article How to. Share Data Between Stored Procedures. However, for the task at hand, passing data from a client, the READONLY. Invoking an SP with a TVPCalling this procedure is straightforward DECLARE mylist integerlisttbltype. INSERT mylistn VALUES9,1. EXEC getproductnames mylist. You can also use TVPs with spexecutesql DECLARE mylist integerlisttbltype. MAX. SELECT sql NSELECT p. Product. ID, p. Product. Name. FROM Northwind. Products p. WHERE p. Product. ID IN SELECT n FROM prodids. INSERT mylist VALUES9,1. EXEC spexecutesql sql, Nprodids integerlisttbltype READONLY, mylist. There are a few peculiarities, though. This does not work EXEC getproductnames NULLbut results in this error message Msg 2. Level 1. 6, State 2, Procedure getproductnames, Line 0. Operand type clash void type is incompatible with integerlisttbltype. It is quite logical when you think of it NULL is a scalar value, not a table value. But what do you think about. EXEC getproductnames. You may expect this to result in an error due to the missing parameter, but instead this runs and produces an empty. The same happens with EXEC getproductnames DEFAULTThe scoop is that a table valued parameter always has the implicit default value of an empty table. Whether this is. good or bad can be disputed, but if there were to be explicit default values, Microsoft would have to invent a lot of. And in most cases, the default value you want is probably the empty table, so it is not entirely unreasonable. Permissions. One thing with table types which is not apparent is that you need permission. This can be demonstrated in this script CREATE USER testuser WITHOUT LOGIN. EXECUTE AS USER testuser. DECLARE p integerlisttbltype. DROP USER testuserWhat we do here is to create a loginless user, and then impersonate that. This is a quick way to test permissions. For more details on impersonation. Giving Permissions through Stored. Procedures. The output from this script is puzzling Msg 2. Level 1. 4, State 5, Line 1. The EXECUTE permission was denied on the object integerlisttbltype, database tempdb, schema dbo. But the message is to be taken by the letter. To be able to use a table type. EXECUTE permission on the type. This does not apply to normal. CLR types. To grant permission. GRANT EXECUTE ON TYPE integerlisttbltype TO testuser. The TYPE prefix is needed to specify the object class. Restrictions. It is maybe not that surprising that you cannot use table valued parameters across linked servers, given that there are many restrictions with linked servers. But it does not stop there you cannot even use table valued parameters across databases. If you try something like USE tempdb. CREATE TYPE tobbe AS TABLE a int NOT NULL PRIMARY KEY. CREATE PROCEDURE tobbesp t tobbe READONLY AS. SELECT a FROM t. CREATE TYPE tobbe AS TABLE a int NOT NULL PRIMARY KEY. DECLARE t tobbe. EXEC tempdb. tobbesp t The error message is Msg 2. Level 1. 6, State 2, Procedure tobbesp, Line 0. Operand type clash tobbe is incompatible with tobbe. And if you try. CREATE PROCEDURE tobbesp t otherdb. READONLY AS. SELECT a FROM t You get the message Msg 1. Level 1. 5, State 2, Procedure tobbesp, Line 1. The type name otherdb. The maximum is 1. This somewhat awkward message informs us that the data type for a parameter cannot be a three part name with a database component. You cannot create stored procedures or. CLR that. take a table valued parameter. But the. other way works you can call a TSQL procedure with a TVP from a CLR procedure, using the same mechanisms you use from a client and which is what we will. Passing Table Valued Parameters from ADO. NETPassing values to TVPs from ADO. NET is very straightforward, and requires very little extra code compared to passing. You need. NET Framework 3. SP1 or higher to have support for TVPs. You can only use TVPs with Sql. Client you cannot use TVPs with the classes in the System. Data. Ole. Db or System. Data. Odbc namespaces. The specifics can be summarised as For the data type you specify Sql. Db. Type. Structured. You specify the name of the table type in the Type. Name property of the parameter. You set the Value property of the parameter to something suitable. Exactly what is suitable thenThere is an MSDN topic that suggests that the three choices are Listlt Sql. Data. Record, a Data. Table or a Db. Data. Reader. It turns out that this is not the full story. I have not been able and nor have I really tried to find the exact requirements, but it seems that you can pass anything that implements IEnumerable and IData. Record, and then Data. Table is a special case that goes beyond that. Exactly what you can use and not use is not particularly interesting.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. Archives
November 2017
Categories |