DataSet.Load Method (IDataReader, LoadOption, String)
Assembly: System.Data (in System.Data.dll)
member Load : reader:IDataReader * loadOption:LoadOption * tables:string -> unit
- Type: System.Data.LoadOption
- Type: System.String
An array of strings, from which the Load method retrieves table name information.
The Load method provides a technique for filling a single DataTable with data, retrieved from an IDataReader instance. This method provides the same functionality, but allows you to load multiple result sets from an IDataReader into multiple tables within a DataSet.
The load operation will fail with an InvalidOperationException if any of the source data columns in the incoming reader are computed columns.
The loadOption parameter allows you to specify how you want the imported data to interact with existing data, and can be any of the values from the LoadOption enumeration. See the documentation for the Load method for more information on using this parameter.
The tables parameter allows you to specify an array of table names, indicating the order of the tables corresponding to each result set loaded from the reader. The Load method attempts to find a table within the DataSet matching the name found in the array of table names, in order. If a matching table is found, that table is loaded with the content of the current result set. If no matching table is found, a table is created using the name supplied in the array of table names, and the new table's schema is inferred from the result set. After each result set, the Load method moves on to the next result set within the reader, until there are no more result sets.
The default namespace associated with DataSet, if any, is associated with each newly created DataTable. The name resolution scheme for this method is the same as that followed by the Fill method of the DbDataAdapter class.
The following Console application example first creates tables and loads data from a reader into a DataSet, using the Load method. The example then adds tables to a DataSet and attempts to fill the tables with data from a DataTableReader. In this example, because the parameters passed to the Load method indicate a table name that does not exist, the Load method creates a new table to match the name passed as a parameter. Once the data has been loaded, the example displays the contents of all its tables in the Console window.