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DataTables-ADO.NET

DataTables

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A

DataSet

is made up of a collection of tables, relationships, and constraints. In ADO.NET,

DataTable

objects are used to represent the tables in a DataSet. A DataTable represents one table of in-memory relational data; the data is local to the .NET-based application in which it resides, but can be populated from a data source such as Microsoft SQL Server using a DataAdapter For more information, see

Populating a DataSet from a DataAdapter

.

The DataTable class is a member of the System.Data namespace within the .NET Framework class library. You can create and use a DataTable independently or as a member of a DataSet, and DataTable objects can also be used in conjunction with other .NET Framework objects, including the

DataView

. You access the collection of tables in a DataSet through the Tables property of the DataSet object.

The schema, or structure of a table is represented by columns and constraints. You define the schema of a DataTable using

DataColumn

objects as well as

ForeignKeyConstraint

and

UniqueConstraint

objects. The columns in a table can map to columns in a data source, contain calculated values from expressions, automatically increment their values, or contain primary key values.

In addition to a schema, a DataTable must also have rows to contain and order data. The

DataRow

class represents the actual data contained in a table. You use the DataRow and its properties and methods to retrieve, evaluate, and manipulate the data in a table. As you access and change the data within a row, the DataRow object maintains both its current and original state.

You can create parent-child relationships between tables using one or more related columns in the tables. You create a relationship between DataTable objects using a

DataRelation

. DataRelation objects can then be used to return the related child or parent rows of a particular row. For more information, see

Adding DataRelations

.

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In This Section

Creating a DataTable

Explains how to create a DataTable and add it to a DataSet.

DataTable Schema Definition

Provides information about creating and using DataColumn objects and constraints.

Manipulating Data in a DataTable

Explains how to add, modify, and delete data in a table. Explains how to use DataTable events to examine changes to data in the table.

Handling DataTable Events

Provides information about the events available for use with a DataTable, including events when column values are modified and rows are added or deleted.

ADO.NET

Describes the ADO.NET architecture and components, and how to use them to access existing data sources and manage application data.

DataSets, DataTables, and DataViews

Provides information about the ADO.NET DataSet including how to create relationships between tables.

Constraint

Provides reference information about the Constraint object.

DataColumn

Provides reference information about the DataColumn object.

DataSet

Provides reference information about the DataSet object.

DataTable

Provides reference information about the DataTable object.

Class Library Overview

Provides an overview of the .NET Framework class library, including the System namespace as well as its second-level namespace, System.Data.

See also

  • ADO.NET Overview

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