C dataadapter not updating
If no primary key exists, incoming rows are appended to the Data Table.When handling batch SQL statements that return multiple results, the implementation of Fill Schema for the OLE DB .When creating Data Table objects, the Fill operation normally creates only column name metadata.However, if the Missing Schema Action property is set to Add With Key, appropriate primary keys, and constraints are also created.Adds or refreshes rows in the Data Set to match those in the data source using the Data Set name, and creates a Data Table named "Table".
If we had carefully crafted SQL statements or stored procedures, it didn't matter.
The Data Set represents a complete set of data including tables, constraints, and relationships among the tables.
Because the Data Set is independent of the data source, a Data Set can include data local to the application, as well as data from multiple data sources. NET Framework has a Data Adapter object: the OLE DB .
Update Batch performed our updates any way that it saw fit.
Some of Microsoft's documentation suggests that our original Recordset was re-created on the server, and the records scrolled through, reconciling the changes between the Recordset from the client and its half-sibling on the server, a very inefficient process. The object provides four properties that allow us to control how updates are made to the server: Select Command, Update Command, Insert Command, and Delete Command.
The connection object associated with the SELECT statement must be valid, but it does not need to be open.