Checking to see if a column exists in a data reader
c#, idatareader
Solution
I ended up finding a solution using the `reader.GetName(int)` method. I created the below method to encompass the logic.
public bool ColumnExists(IDataReader reader, string columnName)
{
for (int i = 0; i < reader.FieldCount; i++)
{
if (reader.GetName(i).Equals(columnName, StringComparison.InvariantCultureIgnoreCase))
{
return true;
}
}
return false;
}
Problem
Is there a way to see if a field exists in an IDataReader-based object w/o just checking for an IndexOutOfRangeException? In essence, I have a method that takes an IDataReader-based object and creates a strongly-typed list of the records. In 1 instance, one data reader has a field that others do not. I don't really want to rewrite all of the queries that feed this method to include some form of this field if I don't have to. The only way I have been able to figure out how to do it so far is to throw the 1 unique field into a try/catch block as shown below. ``` try { tmp.OptionalField = reader["optionalfield"].ToString(); } catch (IndexOutOfRangeException ex) { //do nothing } ``` Is there a cleaner way short of adding the "optional field" to the other queries or copying the loading method so 1 version uses the optional field and the other doesn't? I'm in the 2.0 framework also.