OleDbDataAdapter.Fill Method (DataSet, Object, String)
Assembly: System.Data (in System.Data.dll)
An ADO Recordset or Record object.
The source table used for the table mappings.
The link between ActiveX Data Objects (ADO) and ADO.NET is a one-way operation in that you can copy data from ADO to the DataSet, but any updates to the data must be handled by ADO.NET.
The Fill operation adds the rows to the specified destination DataTable object in the DataSet, creating the DataTable object if it does not already exist. When you create a DataTable object, the Fill operation ordinarily creates only column name metadata. However, if the MissingSchemaAction property is set to AddWithKey, appropriate primary keys and constraints are also created.
If primary key information is present, any duplicate rows are reconciled and only appear one time in the DataTable that corresponds to the DataSet. Primary key information may be set either through FillSchema, by specifying the PrimaryKey property of the DataTable, or by setting the MissingSchemaAction property to AddWithKey.
To function correctly with the .NET Framework Data Provider for OLE DB, AddWithKey requires the native OLE DB provider to obtain required primary key information by setting the DBPROP_UNIQUEROWS property, and then determine which columns are primary key columns by examining DBCOLUMN_KEYCOLUMN in the IColumnsRowset. Alternatively the user may explicitly set the primary key constraints on each DataTable. This ensures that incoming records that match existing records are updated instead of appended.
If the SelectCommand returns the results of an OUTER JOIN, the DataAdapter does not set a PrimaryKey value for the resulting DataTable. You must explicitly define the primary key to make sure that duplicate rows are resolved correctly. For more information, see Defining Primary Keys.
If the Recordset is closed before the starting of the Fill operation, no error results. This is required for handling of multiple results, because queries that do not return rows are indicated by a closed Recordset. The OleDbDataAdapter just calls NextRecordset on the closed Recordset and continues processing.
If an error is encountered while populating the data set, rows added before the occurrence of the error remain in the DataSet. The rest of the operation is aborted.
If the DbDataAdapter object encounters duplicate columns while populating a DataTable, it generates names for the subsequent columns, using the pattern "columnname1", "columnname2", "columnname3", and so on. If the incoming data contains unnamed columns, they are placed in the DataSet according to the pattern "Column1", "Column2", and so on. When multiple result sets are added to the DataSet each result set is placed in a separate table. Additional result sets are named by appending integral values to the specified table name (for example, "Table", "Table1", "Table2", and so on.). Applications that use column and table names should make sure that conflicts with these naming patterns does not occur.
Values in ADO Recordset or Record objects are converted to common language runtime types for storage in the DataSet.
This overload of the Fill method implicitly calls Close on the ADO object when the fill operation is complete.
OleDbDataAdapter custDA = new OleDbDataAdapter(); DataSet custDS = new DataSet(); //Use ADO objects from ADO library (msado15.dll) imported // as.NET library ADODB.dll using TlbImp.exe ADODB.Connection adoConn = new ADODB.Connection(); ADODB.Recordset adoRS = new ADODB.Recordset(); adoConn.Open("Provider=SQLOLEDB;Data Source=localhost;Initial Catalog=Northwind;Integrated Security=SSPI;", "", "", -1); adoRS.Open("SELECT * FROM Customers", adoConn, ADODB.CursorTypeEnum.adOpenForwardOnly, ADODB.LockTypeEnum.adLockReadOnly, 1); custDA.Fill(custDS, adoRS, "Customers"); adoConn.Close();
Available since 1.1