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DataTableReader.GetString(Int32) Method

Definition

Gets the value of the specified column as a string.

public override string GetString (int ordinal);

Parameters

ordinal
Int32

The zero-based column ordinal.

Returns

The value of the specified column.

Exceptions

The index passed was outside the range of 0 to FieldCount - 1.

An attempt was made to retrieve data from a deleted row.

An attempt was made to read or access a column in a closed DataTableReader.

The specified column does not contain a string.

Examples

The following example displays the contents of the column numbered 2 within the passed-in DataTableReader. If the value the column within a particular row is null, the code displays the text <NULL>. If the data within the column of the correct type, the example displays an error message for each row.

private static void PrintColumn(DataTableReader reader)
{
    // Loop through all the rows in the DataTableReader
    while (reader.Read())
    {
        if (reader.IsDBNull(2))
        {
            Console.Write("<NULL>");
        }
        else
        {
            try
            {
                Console.Write(reader.GetString(2));
            }
            catch (InvalidCastException)
            {
                Console.Write("Invalid data type.");
            }
        }
        Console.WriteLine();
    }
}

Remarks

Call IsDBNull to see if there are null values before calling this method.

Applies to

Termék Verziók
.NET Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 2.0, 2.1