I'm importing an excel sheet through SSIS.

One of the columns has values like this

Case_ID

122361
122382
122369
122368
122390
ME_318

when I set up the SSIS source it selects double-precision float [DT_R8] as the data type for the Case ID column and the value with ME_ is ignored.

How doe SSIS select the data type for excel columns and how can I override it.

Thanks