The commonly used public properties of the DataColumn class are listed in Table 24-1.
Property |
Description |
---|---|
AllowDBNull |
Gets or sets whether null values can be stored in the column. |
AutoIncrement |
Gets or sets whether the column automatically increments with each new row added to the table. |
AutoIncrementSeed |
Gets or sets the amount that an automatically incrementing column is incremented each time a row is added to the table. |
AutoIncrementStep |
Gets or sets the starting value for an automatically incrementing column. |
Caption |
Gets or sets the caption for the column used as the default value for the Caption property in controls that support its display. |
ColumnMapping |
Gets or sets how column data is written when it is saved as XML. |
ColumnName |
Gets or sets the name of the column. |
DataType |
Gets or sets the data type of the column data as one of the .NET Framework data types. |
DefaultValue |
Gets or sets the value that is automatically assigned to the column when a new row is created. |
Expression |
Gets or sets an expression that calculates the value of the column. |
MaxLength |
Gets or sets the maximum length for a column with a text data type in characters. |
Namespace |
Gets or sets the XML namespace for the XML representation of the data stored in the column. |
Ordinal |
Gets the position of the column within the column collection of the table. |
Prefix |
Gets or sets the XML prefix for the XML representation of the data stored in the column. |
ReadOnly |
Gets or sets a value that indicates whether the data in the column can be changed once the row containing the column is added to a table. |
Table |
Gets the table that the column has been assigned to. |
Unique |
Gets or sets a value indicating whether the value for each row in the column must be unique. |
The commonly used public collections of the DataColumn class are listed in Table 24-2.
Collection |
Description |
---|---|
ExtendedProperties |
The ExtendedProperties property accesses the PropertyCollection collection that contains custom information for the DataColumn as a collection of key and value pairs. |
The DataColumn class is contained within the System.Data namespace. The DataColumn class inherits from MarshalByValueComponent. It's safe for multithreaded read operations; multithreaded write operations must be synchronized. DataColumn objects cannot be passed between different application domains.