The System.Data.Common namespace contains classes shared by the.NET Framework data providers.

A .NET Framework data provider describes a collection of classes used to access a data source, such as a database, in the managed space. Supported providers include the .NET Framework Data Provider for ODBC, the .NET Framework Data Provider for OLEDB, the .NET Framework Data Provider for Oracle, and the .NET Framework Data Provider for SQL Server. The classes in System.Data.Common are intended to give developers a way to write ADO.NET code that will work against all .NET Framework data providers.

For conceptual information about how to use this namespace when programming with the.NET Framework, see Writing Provider Independent Code in ADO.NET.

 Classes

	Class	Description
	DataAdapter	Represents a set of SQL commands and a database connection that are used to fill the DataSet and update the data source.
	DataColumnMapping	Contains a generic column mapping for an object that inherits from DataAdapter. This class cannot be inherited.
	DataColumnMappingCollection	Contains a collection of DataColumnMapping objects.
	DataTableMapping	Contains a description of a mapped relationship between a source table and a DataTable. This class is used by a DataAdapter when populating a DataSet.
	DataTableMappingCollection	A collection of DataTableMapping objects. This class cannot be inherited.
	DbCommand	Represents an SQL statement or stored procedure to execute against a data source. Provides a base class for database-specific classes that represent commands.
	DbCommandBuilder	Automatically generates single-table commands used to reconcile changes made to a DataSet with the associated database. This is an abstract class that can only be inherited.
	DbConnection	Represents a connection to a database.
	DbConnectionStringBuilder	Provides a base class for strongly typed connection string builders.
	DbDataAdapter	Aids implementation of the IDbDataAdapter interface. Inheritors of DbDataAdapter implement a set of functions to provide strong typing, but inherit most of the functionality needed to fully implement a DataAdapter.
	DBDataPermission	Enables a .NET Framework data provider to help ensure that a user has a security level adequate for accessing data.
	DBDataPermissionAttribute	Associates a security action with a custom security attribute.
	DbDataReader	Reads a forward-only stream of rows from a data source.
	DbDataRecord	Implements IDataRecord and ICustomTypeDescriptor, and provides data binding support for DbEnumerator.
	DbDataSourceEnumerator
	DbEnumerator	Exposes the GetEnumerator method, which supports a simple iteration over a collection by a .NET Framework data provider.
	DbException	The base class for all exceptions thrown on behalf of the data source.
	DbMetaDataCollectionNames	Provides a list of constants for the well-known MetaDataCollections: DataSourceInformation, DataTypes, MetaDataCollections, ReservedWords, and Restrictions.
	DbMetaDataColumnNames	Provides static values that are used for the column names in the MetaDataCollection objects contained in the DataTable. The DataTable is created by the GetSchema method.
	DbParameter	Represents a parameter to a DbCommand and optionally, its mapping to a DataSet column.
	DbParameterCollection	The base class for a collection of parameters relevant to a DbCommand.
	DbProviderConfigurationHandler
	DbProviderFactories	Represents a set of static methods for creating one or more instances of DbProviderFactory classes.
	DbProviderFactoriesConfigurationHandler
	DbProviderFactory	Represents a set of methods for creating instances of a provider's implementation of the data source classes.
	DbProviderSpecificTypePropertyAttribute	Identifies which provider-specific property in the strongly typed parameter classes is to be used when setting a provider-specific type.
	DbTransaction	The base class for a transaction.
	RowUpdatedEventArgs	Provides data for the RowUpdated event of a .NET Framework data provider.
	RowUpdatingEventArgs	Provides the data for the RowUpdating event of a .NET Framework data provider.
	SchemaTableColumn	Describes the column metadata of the schema for a database table.
	SchemaTableOptionalColumn	Describes optional column metadata of the schema for a database table.

 Enumerations

	Enumeration	Description
	CatalogLocation	Indicates the position of the catalog name in a qualified table name in a text command.
	GroupByBehavior	Specifies the relationship between the columns in a GROUP BY clause and the non-aggregated columns in the select-list of a SELECT statement.
	IdentifierCase	Specifies how identifiers are treated by the data source when searching the system catalog.
	SupportedJoinOperators	Specifies what types of Transact-SQL join statements are supported by the data source.