The DataTable Class

The DataTable Class

You use an object of the DataTable class to represent a table. You can also store multiple DataTable objects in a DataSet. Table 11.1 shows some of the DataTable properties.

Table 11.1: DataTable PROPERTIES

PROPERTY

TYPE

DESCRIPTION

CaseSensitive

bool

Gets or sets a bool value that indicates whether string comparisons within DataTable objects are case-sensitive.

ChildRelations

DataRelationCollection

Gets the collection of relations (DataRelationCollection) that allows navigation from a parent table to a child table. A DataRelationCollection consists of DataRelation objects.

Columns

DataColumnCollection

Gets the collection of columns (DataColumnCollection) that contains DataColumn objects that represent the columns in the DataTable object.

Constraints

ConstraintCollection

Gets the collection of constraints (ConstraintCollection) that contains Constraint objects that represent primary key (UniqueConstraint) or foreign key constraints (ForeignKeyConstraint) in the DataTable object.

DataSet

DataSet

Gets the DataSet to which the DataTable belongs.

HasErrors

bool

Returns a bool value that indicates whether any of the rows in the DataTable have errors.

PrimaryKey

DataColumn[]

Gets or sets an array of DataColumn objects that are the primary keys for the DataTable.

Rows

DataRowCollection

Gets the collection of rows (DataRowCollection) that contains the DataRow objects stored in the DataTable.

TableName

string

Gets or sets the name of the DataTable object.

Table 11.2 shows some of the DataTable methods.

Table 11.2: DataTable METHODS

METHOD

RETURN TYPE

DESCRIPTION

AcceptChanges()

void

Commits all the changes made to the DataTable object since it was loaded or since the last time the AcceptChanges() method was called.

Clear()

void

Removes all rows from the DataTable object.

Clone()

DataTable

Clones the structure of the DataTable object and returns that clone.

Compute()

object

Computes the given expression on the current rows that pass the filter criteria.

GetChanges()

DataTable

Overloaded. Returns a copy of the DataTable object since it was last loaded or since the last time the AcceptChanges() method was called.

GetErrors()

DataRow[]

Overloaded. Gets a copy of all the DataRow objects that have errors.

LoadDataRow()

DataRow

Finds and updates a specified DataRow object. If no matching object is found, a new row is created using the specified values.

NewRow()

DataRow

Creates a new DataRow object in the DataTable.

RejectChanges()

void

Undoes all the changes made to the DataTable object since it was created or since the last time the AcceptChanges() method was called.

Select()

DataRow[]

Overloaded. Returns the array of DataRow objects stored in the DataTable that match the specified filter string. You can also pass a string containing details on how to sort the DataRow objects.

Table 11.3 shows some of the DataTable events.

Table 11.3: DataTable EVENTS

EVENT

EVENT HANDLER

DESCRIPTION

ColumnChanging

DataColumnChangeEventHandler

Fires before a changed DataColumn value is committed in a DataRow.

ColumnChanged

DataColumnChangeEventHandler

Fires after a changed DataColumn value is committed in a DataRow.

RowChanging

DataRowChangeEventHandler

Fires before a changed DataRow is committed in a DataTable.

RowChanged

DataRowChangeEventHandler

Fires after a changed DataRow is committed in a DataTable.

RowDeleting

DataRowChangeEventHandler

Fires before a DataRow is deleted from a DataTable.

RowDeleted

DataRowChangeEventHandler

Fires after a DataRow is deleted from a DataTable.




Mastering C# Database Programming
Mastering the SAP Business Information Warehouse: Leveraging the Business Intelligence Capabilities of SAP NetWeaver
ISBN: 0764596373
EAN: 2147483647
Year: 2003
Pages: 181

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