SQL Server 2000 Stored Procedure & XML Programming in VS .NET

Generation Data Matrix in VS .NET SQL Server 2000 Stored Procedure & XML Programming

SQL Server 2000 Stored Procedure & XML Programming
Data Matrix Decoder In .NET Framework
Using Barcode Control SDK for Visual Studio .NET Control to generate, create, read, scan barcode image in VS .NET applications.
Encoding DataMatrix In VS .NET
Using Barcode printer for VS .NET Control to generate, create Data Matrix 2d barcode image in .NET applications.
Triggers on Views
Recognizing ECC200 In Visual Studio .NET
Using Barcode decoder for Visual Studio .NET Control to read, scan read, scan image in .NET applications.
Bar Code Printer In .NET
Using Barcode creation for .NET Control to generate, create barcode image in .NET applications.
Instead-of triggers can be defined on views also. In the following example, a trigger is created on a view that displays fields from two tables:
Bar Code Scanner In .NET Framework
Using Barcode recognizer for .NET framework Control to read, scan read, scan image in VS .NET applications.
ECC200 Drawer In C#.NET
Using Barcode generation for VS .NET Control to generate, create DataMatrix image in .NET framework applications.
Create View dbo.vEquipment AS Select Equipment.EquipmentId, Equipment.Make, Equipment.Model, EqType.EqType From Equipment Inner Join EqType On Equipment.EqTypeId = EqType.EqTypeId Go Create Trigger itr_vEquipment_I On dbo.vEquipment instead of Insert As -- If the EqType is new, insert it If exists(select EqType from inserted where EqType not in (select EqType from EqType)) -- we need to insert the new ones insert into EqType(EqType) select EqType from inserted where EqType not in (select EqType from EqType) -- now you can insert new equipment Insert into Equipment(Make, Model, EqTypeId) Select inserted.Make, inserted.Model, EqType.EqTypeId From inserted Inner Join EqType On inserted.EqType = EqType.EqType GO Insert Into vEquipment(EquipmentId, Make, Model, EqType) Values (-777, 'Microsoft', 'Natural Keyboard', 'keyboard')
DataMatrix Generator In .NET Framework
Using Barcode generation for ASP.NET Control to generate, create Data Matrix image in ASP.NET applications.
Data Matrix Creation In VB.NET
Using Barcode creation for VS .NET Control to generate, create ECC200 image in Visual Studio .NET applications.
C h a p t e r 8 : S p e c i a l Ty p e s o f P r o c e d u r e s
Barcode Drawer In VS .NET
Using Barcode creation for VS .NET Control to generate, create bar code image in Visual Studio .NET applications.
Generating GS1 DataBar Stacked In VS .NET
Using Barcode encoder for .NET framework Control to generate, create GS1 DataBar Stacked image in .NET applications.
The trigger first examines whether the Inserted table contains EqType values that do not exist in EqTable. If they exist, they will be inserted in the EqType table. At the end, values from the Inserted table are added to the Equipment table. The previous example illustrates one unusual feature in the use of Instead-of triggers on views. Since EquipmentId is referenced by the view, it can (and must) be specified by the modification statement (Insert statement). The trigger can (and will) ignore the specified value since it is inserted automatically (EquipmentId is an identity field in the base table). The reason for this behavior is that the Inserted and Deleted tables have different structures from the base tables on which the view is based. They have the same structure as the Select statement inside the view. Columns in the view can be nullable or not nullable. The column is nullable if its expression in the Select list of the view satisfies one of the following criteria: The view column references a base table column that is nullable. The view column expression uses arithmetic operators or functions. If the column does not allow nulls, an Insert statement must provide a value for it. This is the reason a value for EquipmentId column was needed in the previous example. An Update statement must provide values for all nonnullable columns referenced by the Set clause in a view with an Instead-of update trigger.
USS-128 Encoder In .NET Framework
Using Barcode creator for Visual Studio .NET Control to generate, create UCC-128 image in VS .NET applications.
Printing UPC E In Visual Studio .NET
Using Barcode printer for .NET framework Control to generate, create UPC E image in .NET applications.
NOTE
Scan Data Matrix In None
Using Barcode reader for Software Control to read, scan read, scan image in Software applications.
Barcode Scanner In Java
Using Barcode decoder for Java Control to read, scan read, scan image in Java applications.
You must specify values even for view columns that are mapped to timestamp, Identity, or computed base table columns.
Paint UPC-A Supplement 5 In Java
Using Barcode generation for Android Control to generate, create UPC-A Supplement 5 image in Android applications.
Bar Code Creation In None
Using Barcode generator for Software Control to generate, create barcode image in Software applications.
You can use the AllowNull property of the ColumnProperty() function (table function) to examine which fields are nullable from code.
Generate Bar Code In Java
Using Barcode encoder for BIRT reports Control to generate, create bar code image in BIRT reports applications.
Generate Bar Code In None
Using Barcode encoder for Excel Control to generate, create barcode image in Office Excel applications.
NOTE
Recognizing Bar Code In Visual C#.NET
Using Barcode reader for VS .NET Control to read, scan read, scan image in Visual Studio .NET applications.
Making Bar Code In None
Using Barcode drawer for Online Control to generate, create barcode image in Online applications.
The previous code example is much more important than you might think. It allows you to insert a whole set of records at one time into the view (actually to the set of base tables behind the view). Before Instead-of triggers, you had to do this record by record with a stored procedure. This capability is very useful for loading information into a SQL Server database. For example, you can load information from a denormalized source (such as a flat file) and store it in a set of normalized, linked tables.
Another unusual feature of Instead-of triggers is the fact that they support text, ntext, and image columns in Inserted and Deleted tables. After triggers cannot
SQL Server 2000 Stored Procedure & XML Programming
handle these data types. In base tables, text, ntext, and image columns actually contain pointers to the pages holding data. In Inserted and Deleted tables, text, ntext, and image columns are stored as continuous strings within each row. No pointers are stored in these tables, and therefore the use of the Textptr() and Textvalid() functions and the Readtext, Updatetext, and Writetext statements is not permitted. All other uses are valid, such as references in the Select list or Where clause, or use of Charindex(), Patindex(), or Substring() functions.
Copyright © OnBarcode.com . All rights reserved.