Does My SqlDataReader Contain This Column?

How to Check for Column Name Existence in a SqlDataReader

In data access layers, creating a consistent method for handling different stored procedures can be challenging, especially when working with columns that are not shared across all procedures. To overcome this issue in C#, an effective solution is to check if a specific column exists within a SqlDataReader object.

To accomplish this, an extension method can be implemented:

public static class DataRecordExtensions
{
    public static bool HasColumn(this IDataRecord dr, string columnName)
    {
        for (int i = 0; i < dr.FieldCount; i++)
        {
            if (dr.GetName(i).Equals(columnName, StringComparison.InvariantCultureIgnoreCase))
                return true;
        }
        return false;
    }
}

This method iterates through the fields of the SqlDataReader and compares the names with the provided column name, disregarding case. If the column is found, it returns true. This approach is preferred over using exceptions for control logic, which can impact performance and result in false positives in exception handling.

Additionally, while using GetSchemaTable() is another option, it is not fully supported and exhibits performance overhead. Therefore, looping through the fields is a reliable and performant method for checking column existence in a SqlDataReader object.

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