OleDbConnection.GetOleDbSchemaTable(Guid, Object[]) Method

Definition

Namespace:

System.Data.OleDb

Assembly:

System.Data.OleDb.dll

Package:

System.Data.OleDb v9.0.0-rc.2.24473.5

Source:

OleDbConnection.cs

Returns schema information from a data source as indicated by a GUID, and after it applies the specified restrictions.

public:
 System::Data::DataTable ^ GetOleDbSchemaTable(Guid schema, cli::array <System::Object ^> ^ restrictions);

public System.Data.DataTable? GetOleDbSchemaTable (Guid schema, object?[]? restrictions);

member this.GetOleDbSchemaTable : Guid * obj[] -> System.Data.DataTable

Public Function GetOleDbSchemaTable (schema As Guid, restrictions As Object()) As DataTable

Parameters

schema

Guid

One of the OleDbSchemaGuid values that specifies the schema table to return.

restrictions

Object[]

An Object array of restriction values. These are applied in the order of the restriction columns. That is, the first restriction value applies to the first restriction column, the second restriction value applies to the second restriction column, and so on.

Returns

DataTable

A DataTable that contains the requested schema information.

Exceptions

OleDbException

The specified set of restrictions is invalid.

InvalidOperationException

The OleDbConnection is closed.

ArgumentException

The specified schema rowset is not supported by the OLE DB provider.

-or-

The schema parameter contains a value of DbInfoLiterals and the restrictions parameter contains one or more restrictions.

Examples

The following sample returns a list of tables in a database.

static DataTable GetSchemaTable(string connectionString)
{
    using (OleDbConnection connection = new
               OleDbConnection(connectionString))
    {
        connection.Open();
        DataTable schemaTable = connection.GetOleDbSchemaTable(
            OleDbSchemaGuid.Tables,
            new object[] { null, null, null, "TABLE" });
        return schemaTable;
    }
}

Public Function GetSchemaTable(ByVal connectionString As String) _
    As DataTable

    Using connection As New OleDbConnection(connectionString)
        connection.Open()

        Dim schemaTable As DataTable = _
            connection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, _
            New Object() {Nothing, Nothing, Nothing, "TABLE"})
        Return schemaTable
    End Using
End Function

Remarks

The schema table is returned as a DataTable that has the same format as the OLE DB schema rowset specified by the schema parameter. Use the restrictions parameter to filter the rows to be returned in the DataTable (for example, by specifying restrictions for table name, type, owner, or schema). When you pass values in the array, include empty strings or nulls for array elements that do not contain values. If you pass an empty array to restrictions, all rows (one for each table) are returned in default order. Values in the array correspond to the order of the columns in the source table and DataTable. Each element in the restrictions array is compared with the content of the corresponding column in the schema rowset. For example, the first element in the restrictions array is compared to first column in the rowset. If a restriction element is not null, only rows from the schema rowset that exactly match the value of the restriction are added to the resulting DataTable.

The OleDbConnection method calls the underlying OLE DB IDBSchemaRowset::GetRowset method using standard common language runtime conversion rules. For more information, see COM Data Types.

You can retrieve information about literals by using DbInfoLiterals. This provides information equivalent to calling the OLE DB IDBInfo::GetLiteralInfo interface, or the ADO Connection.OpenSchema method with the adSchemaDBInfoLiterals constant.

See also

• Connecting to Data Sources