Updating database with dataset chinese dating edicate
This means you have to load the data in parent then child order. You have to make sure that every row in the child Data Table will have a corresponding parent row in the parent Data Table.This also means that you have to make sure to call End Edit on any new parent Binding Source before any children can be added.if NULLs aren’t being allowed then you have to set those values).One way to handle this is to add code to set default values in the Table New Row handler on the Data Table.However if you’re using MS Access then there’s one thing that Visual Studio doesn’t do because it’s not supported when using Access.How Parent-Child Inserts Work When Visual Studio generates the insert commands on a SQL-Server Table Adapter it looks to see if the table’s primary keys are auto-generated (identity columns) and if so, Visual Studio will write an additional statement to retrieve the key using the SCOPE_IDENTITY functionality of SQL Server.When in the Data Set designer, if you look at the insert statement in the properties window for the SQLTable Adapter you will see two statements separated by a semi-colon: INSERT INTO [dbo].[Products] ([Product Name], [Supplier ID], [Category ID], [Quantity Per Unit], [Unit Price], [Units In Stock], [Units On Order], [Reorder Level], [Discontinued]) VALUES (@Product Name, @Supplier ID, @Category ID, @Quantity Per Unit, @Unit Price, @Units In Stock, @Units On Order, @Reorder Level, @Discontinued SQL Server supports batch statements through ADO.NET commands so this will populate the primary key back in the Data Row inside the Data Set as each row is inserted into the database.
Setting up the Parent-Child Data Set The first step is to make sure you set up the tables in your Access database to use the Auto Number feature for the primary keys on the rows.
In this example I just am calling End Edit on the Categories Binding Source when the user selects the grid.
Note that anytime you call End Edit and flush the data to the Data Table, the row must not fail any constraints either (i.e.
Now that we have keys cascading we just need to write code to handle the Row Updated event on the Data Adapter inside the Table Adapter partial class.
Table Adapters are generated classes that Visual Studio creates for us from the Data Set designer.