The type of data stored in thecolumn.
[Visual Basic] Public Property DataType As Type [C#] public Type DataType {get; set;} [C++] public: __property Type* get_DataType(); public: __property void set_DataType(Type*); [JScript] public function get DataType() : Type; public function set DataType(Type);
A Type object that represents the column's data type.
Exception Type | Condition |
---|---|
ArgumentException | The column already has data stored. |
ArgumentException | AutoIncrement is true, but the value is set to a type a unsupported by AutoIncrement. |
Setting the DataType value is critical to ensuring the correct creation and updating of data in a DBMS.
The DataType property supports the base data types shown below:
Note The following types are not supported by Visual Basic: DateTime, UInt16, UInt32, UInt64, and TimeSpan.
An exception is thrown when changing this property after the column has begun storing data.
If AutoIncrement is set to true before setting the DataType property, and you attempt to set the type to anything except an integer type, an exception will be thrown.
The following example adds columns of several data types to a DataTable, then adds one row to the table.
[Visual Basic]
Public Function MakeDataTable() As DataTable Dim myTable As DataTable Dim row As DataRow Dim r As Integer Dim c As Integer myTable = New DataTable("My Table") myTable.Columns.Add New DataColumn("StringCol", System.Type.GetType("System.String")) myTable.Columns.Add New DataColumn("ByteCol", System.Type.GetType("System.Byte")) myTable.Columns.Add New DataColumn("Int16Col", System.Type.GetType("System.Int16")) myTable.Columns.Add New DataColumn("Int32Col", System.Type.GetType("System.Int32")) myTable.Columns.Add New DataColumn("BooleanCol", System.Type.GetType("System.Boolean")) myTable.Columns.Add New DataColumn("TimeSpanCol", System.Type.GetType("System.TimeSpan")) myTable.Columns.Add New DataColumn("DateTimeCol", System.Type.GetType("System.DateTime")) myTable.Columns.Add New DataColumn("CurrencyCol", System.Type.GetType("System.Currency")) ' Populate one row with values. row = myTable.NewRow row(0) = "Item Name" ' Can't do column1 because it takes a byte. row(2) = 32767 row(3) = 2147483647 row(4) = True row(5) = "10675199.02:48:05.477" row(6) = now row(7) = 64000 myTable.Rows.Add row MakeDataTable = myTable nd Function
DataColumn Class | DataColumn Members | System.Data Namespace | Type | GetType