System.Data Namespace
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Provides access to classes that represent the ADO.NET architecture. ADO.NET lets you build components that efficiently manage data from multiple data sources.
Classes
Constraint |
Represents a constraint that can be enforced on one or more DataColumn objects. |
ConstraintCollection |
Represents a collection of constraints for a DataTable. |
ConstraintException |
Represents the exception that is thrown when attempting an action that violates a constraint. |
DataColumn |
Represents the schema of a column in a DataTable. |
DataColumnChangeEventArgs |
Provides data for the ColumnChanging event. |
DataColumnCollection |
Represents a collection of DataColumn objects for a DataTable. |
DataException |
Represents the exception that is thrown when errors are generated using ADO.NET components. |
DataReaderExtensions |
Provides extension methods for DbDataReader. |
DataRelation |
Represents a parent/child relationship between two DataTable objects. |
DataRelationCollection |
Represents the collection of DataRelation objects for this DataSet. |
DataRow |
Represents a row of data in a DataTable. |
DataRowBuilder |
The |
DataRowChangeEventArgs |
Provides data for the RowChanged, RowChanging, OnRowDeleting(DataRowChangeEventArgs), and OnRowDeleted(DataRowChangeEventArgs) events. |
DataRowCollection |
Represents a collection of rows for a DataTable. |
DataRowComparer |
Returns a singleton instance of the DataRowComparer<TRow> class. |
DataRowComparer<TRow> |
Compares two DataRow objects for equivalence by using value-based comparison. |
DataRowExtensions |
Defines the extension methods to the DataRow class. This is a static class. |
DataRowView |
Represents a customized view of a DataRow. |
DataSet |
Represents an in-memory cache of data. |
DataSetSchemaImporterExtension |
This member supports the .NET Framework infrastructure and is not intended to be used directly from your code. |
DataSysDescriptionAttribute |
Marks a property, event, or extender with a description. Visual designers can display this description when referencing the member. |
DataTable |
Represents one table of in-memory data. |
DataTableClearEventArgs |
Provides data for the Clear() method. |
DataTableCollection |
Represents the collection of tables for the DataSet. |
DataTableExtensions |
Defines the extension methods to the DataTable class. DataTableExtensions is a static class. |
DataTableNewRowEventArgs |
Provides data for the NewRow() method. |
DataTableReader |
The DataTableReader obtains the contents of one or more DataTable objects in the form of one or more read-only, forward-only result sets. |
DataView |
Represents a databindable, customized view of a DataTable for sorting, filtering, searching, editing, and navigation. The DataView does not store data, but instead represents a connected view of its corresponding DataTable. Changes to the DataView's data will affect the DataTable. Changes to the DataTable's data will affect all DataViews associated with it. |
DataViewManager |
Contains a default DataViewSettingCollection for each DataTable in a DataSet. |
DataViewSetting |
Represents the default settings for ApplyDefaultSort, DataViewManager, RowFilter, RowStateFilter, Sort, and Table for DataViews created from the DataViewManager. |
DataViewSettingCollection |
Contains a read-only collection of DataViewSetting objects for each DataTable in a DataSet. |
DBConcurrencyException |
The exception that is thrown by the DataAdapter during an insert, update, or delete operation if the number of rows affected equals zero. |
DeletedRowInaccessibleException |
Represents the exception that is thrown when an action is tried on a DataRow that has been deleted. |
DuplicateNameException |
Represents the exception that is thrown when a duplicate database object name is encountered during an add operation in a DataSet -related object. |
EntityCommandCompilationException |
Represents errors that occur during command compilation; when a command tree could not be produced to represent the command text. |
EntityCommandExecutionException |
Represents errors that occur when the underlying storage provider could not execute the specified command. This exception usually wraps a provider-specific exception. |
EntityException |
Represents Entity Framework-related errors that occur in the |
EntityKey |
Provides a durable reference to an object that is an instance of an entity type. |
EntityKeyMember |
Represents a key name and value pair that is part of an EntityKey. |
EntitySqlException |
Represents errors that occur when parsing Entity SQL command text. This exception is thrown when syntactic or semantic rules are violated. |
EnumerableRowCollection |
Represents a collection of DataRow objects returned from a LINQ to DataSet query. This API supports the .NET infrastructure and is not intended to be used directly from your code. |
EnumerableRowCollection<TRow> |
Represents a collection of DataRow objects returned from a query. |
EnumerableRowCollectionExtensions |
Contains the extension methods for the data row collection classes. |
EvaluateException |
Represents the exception that is thrown when the Expression property of a DataColumn cannot be evaluated. |
FillErrorEventArgs |
Provides data for the FillError event of a DbDataAdapter. |
ForeignKeyConstraint |
Represents an action restriction enforced on a set of columns in a primary key/foreign key relationship when a value or row is either deleted or updated. |
InRowChangingEventException |
Represents the exception that is thrown when you call the EndEdit() method within the RowChanging event. |
InternalDataCollectionBase |
Provides the base functionality for creating collections. |
InvalidCommandTreeException |
The exception that is thrown to indicate that a command tree is invalid. This exception is currently not thrown anywhere in the Entity Framework. |
InvalidConstraintException |
Represents the exception that is thrown when incorrectly trying to create or access a relation. |
InvalidExpressionException |
Represents the exception that is thrown when you try to add a DataColumn that contains an invalid Expression to a DataColumnCollection. |
MappingException |
The exception that is thrown when mapping related service requests fail. |
MergeFailedEventArgs |
Occurs when a target and source |
MetadataException |
The exception that is thrown when metadata related service requests fails. |
MissingPrimaryKeyException |
Represents the exception that is thrown when you try to access a row in a table that has no primary key. |
NoNullAllowedException |
Represents the exception that is thrown when you try to insert a null value into a column where AllowDBNull is set to |
ObjectNotFoundException |
The exception that is thrown when an object is not present. |
OperationAbortedException |
This exception is thrown when an ongoing operation is aborted by the user. |
OptimisticConcurrencyException |
The exception that is thrown when an optimistic concurrency violation occurs. |
OrderedEnumerableRowCollection<TRow> |
Represents a collection of ordered DataRow objects returned from a query. |
PropertyCollection |
Represents a collection of properties that can be added to DataColumn, DataSet, or DataTable. |
PropertyConstraintException |
Property constraint exception class. Note that this class has state - so if you change even its internals, it can be a breaking change. |
ProviderIncompatibleException |
The exception that is thrown when the underlying data provider is incompatible with the Entity Framework. |
ReadOnlyException |
Represents the exception that is thrown when you try to change the value of a read-only column. |
RowNotInTableException |
Represents the exception that is thrown when you try to perform an operation on a DataRow that is not in a DataTable. |
StateChangeEventArgs |
Provides data for the state change event of a .NET data provider. |
StatementCompletedEventArgs |
Provides additional information for the StatementCompleted event. |
StrongTypingException |
The exception that is thrown by a strongly typed DataSet when the user accesses a |
SyntaxErrorException |
Represents the exception that is thrown when the Expression property of a DataColumn contains a syntax error. |
TypedDataSetGenerator |
Used to create a strongly typed DataSet. |
TypedDataSetGeneratorException |
The exception that is thrown when a name conflict occurs while generating a strongly typed DataSet. |
TypedTableBase<T> |
This type is used as a base class for typed-DataTable object generation by Visual Studio and the XSD.exe .NET Framework tool, and is not intended to be used directly from your code. |
TypedTableBaseExtensions |
Contains the extension methods for the TypedTableBase<T> class. |
UniqueConstraint |
Represents a restriction on a set of columns in which all values must be unique. |
UpdateException |
The exception that is thrown when modifications to object instances cannot be persisted to the data source. |
VersionNotFoundException |
Represents the exception that is thrown when you try to return a version of a DataRow that has been deleted. |
Interfaces
IColumnMapping |
Associates a data source column with a DataSet column, and is implemented by the DataColumnMapping class, which is used in common by .NET data providers. |
IColumnMappingCollection |
Contains a collection of DataColumnMapping objects, and is implemented by the DataColumnMappingCollection, which is used in common by .NET data providers. |
IDataAdapter |
Allows an object to implement a DataAdapter, and represents a set of methods and mapping action-related properties that are used to fill and update a DataSet and update a data source. IDbDataAdapter instances are for data sources that are (or resemble) relational databases with textual commands (like Transact-SQL), while IDataAdapter instances could can use any type of data source. |
IDataParameter |
Represents a parameter to a Command object, and optionally, its mapping to DataSet columns; and is implemented by .NET data providers that access data sources. |
IDataParameterCollection |
Collects all parameters relevant to a Command object and their mappings to DataSet columns, and is implemented by .NET data providers that access data sources. |
IDataReader |
Provides a means of reading one or more forward-only streams of result sets obtained by executing a command at a data source, and is implemented by .NET data providers that access relational databases. |
IDataRecord |
Provides access to the column values within each row for a |
IDbCommand |
Represents an SQL statement that is executed while connected to a data source, and is implemented by .NET data providers that access relational databases. |
IDbConnection |
Represents an open connection to a data source, and is implemented by .NET data providers that access relational databases. |
IDbDataAdapter |
Represents a set of command-related properties that are used to fill the DataSet and update a data source, and is implemented by .NET data providers that access relational databases. |
IDbDataParameter |
Used by the Visual Basic .NET Data Designers to represent a parameter to a Command object, and optionally, its mapping to DataSet columns. |
IDbTransaction |
Represents a transaction to be performed at a data source, and is implemented by .NET data providers that access relational databases. |
IExtendedDataRecord |
Provides access to the column values within each row of a DbDataRecord for a DbDataReader. |
ITableMapping |
Associates a source table with a table in a DataSet, and is implemented by the DataTableMapping class, which is used in common by .NET data providers. |
ITableMappingCollection |
Contains a collection of TableMapping objects, and is implemented by the DataTableMappingCollection, which is used in common by .NET data providers. |
Enums
AcceptRejectRule |
Determines the action that occurs when the AcceptChanges() or RejectChanges() method is invoked on a DataTable with a ForeignKeyConstraint. |
CommandBehavior |
Provides a description of the results of the query and its effect on the database. |
CommandType |
Specifies how a command string is interpreted. |
ConflictOption |
Specifies how conflicting changes to the data source will be detected and resolved. |
ConnectionState |
Describes the current state of the connection to a data source. |
DataRowAction |
Describes an action performed on a DataRow. |
DataRowState |
Gets the state of a DataRow object. |
DataRowVersion |
Describes the version of a DataRow. |
DataSetDateTime |
Describes the serialization format for DateTime columns in a DataSet. |
DataViewRowState |
Describes the version of data in a DataRow. |
DbType |
Specifies the data type of a field, a property, or a |
EntityState |
The state of an entity object. |
IsolationLevel |
Specifies the transaction locking behavior for the connection. |
KeyRestrictionBehavior |
Identifies a list of connection string parameters identified by the |
LoadOption |
Controls how the values from the data source will be applied to existing rows when using the Load or Load method. |
MappingType |
Specifies how a DataColumn is mapped. |
MissingMappingAction |
Determines the action that occurs when a mapping is missing from a source table or a source column. |
MissingSchemaAction |
Specifies the action to take when adding data to the DataSet and the required DataTable or DataColumn is missing. |
ParameterDirection |
Specifies the type of a parameter within a query relative to the DataSet. |
PropertyAttributes |
Specifies the attributes of a property. |
Rule |
Indicates the action that occurs when a ForeignKeyConstraint is enforced. |
SchemaSerializationMode |
Indicates the schema serialization mode for a typed DataSet. |
SchemaType |
Specifies how to handle existing schema mappings when performing a FillSchema(DataSet, SchemaType) operation. |
SerializationFormat |
Determines the serialization format for a DataSet. |
SqlDbType |
Specifies SQL Server-specific data type of a field, property, for use in a SqlParameter. |
StatementType |
Specifies the type of SQL query to be used by the OleDbRowUpdatedEventArgs, OleDbRowUpdatingEventArgs, SqlRowUpdatedEventArgs, or SqlRowUpdatingEventArgs class. |
UpdateRowSource |
Specifies how query command results are applied to the row being updated. |
UpdateStatus |
Specifies the action to take with regard to the current and remaining rows during an Update(DataSet). |
XmlReadMode |
Specifies how to read XML data and a relational schema into a DataSet. |
XmlWriteMode |
Specifies how to write XML data and a relational schema from a DataSet. |
Delegates
DataColumnChangeEventHandler |
Represents the method that will handle the ColumnChanging event. |
DataRowChangeEventHandler |
Represents the method that will handle the RowChanging, RowChanged, RowDeleting, and RowDeleted events of a DataTable. |
DataTableClearEventHandler |
Represents the method that handles the Clear() method. |
DataTableNewRowEventHandler |
Represents the method that handles the NewRow() method. |
FillErrorEventHandler |
Represents the method that will handle the FillError event. |
MergeFailedEventHandler |
Represents the method that will handle the MergeFailed event. |
StateChangeEventHandler |
Represents the method that will handle the StateChange event. |
StatementCompletedEventHandler |
The delegate type for the event handlers of the StatementCompleted event. |
Remarks
In a disconnected scenario such as the Internet, ADO.NET provides the tools to request, update, and reconcile data in multiple tier systems. The ADO.NET architecture is also implemented in client applications, such as Windows Forms, or HTML pages created by ASP.NET.
The centerpiece of the ADO.NET architecture is the DataSet class. Each DataSet can contain multiple DataTable objects, with each DataTable containing data from a single data source, such as SQL Server.
Each DataTable contains a DataColumnCollection--a collection of DataColumn objects--that determines the schema of each DataTable. The DataType property determines the type of data held by the DataColumn. The ReadOnly and AllowDBNull properties let you further guarantee data integrity. The Expression property lets you construct calculated columns.
If a DataTable participates in a parent/child relationship with another DataTable, the relationship is constructed by adding a DataRelation to the DataRelationCollection of a DataSet object. When such a relation is added, a UniqueConstraint and a ForeignKeyConstraint are both created automatically, depending on the parameter settings for the constructor. The UniqueConstraint guarantees that values that are contained in a column are unique. The ForeignKeyConstraint determines what action will happen to the child row or column when a primary key value is changed or deleted.
Using the System.Data.SqlClient namespace (the.NET Framework Data Provider for SQL Server), the System.Data.Odbc namespace (the.NET Framework Data Provider for ODBC), the System.Data.OleDb namespace (the.NET Framework Data Provider for OLE DB), or the System.Data.OracleClient namespace (the .NET Framework Data Provider for Oracle), you can access a data source to use together with a DataSet. Each.NET Framework data provider has a corresponding DataAdapter that you use as a bridge between a data source and a DataSet.