c# - SQLDataAdapter changing value type returned from SQL -

in c# project, executing query against sql 2014 database retrieve employee data, including periodend stored in database decimal (i.e., nov 17, 2016 stored 20161117). database querying not our product cannot change type datetime field.

here sql script being executed:

select distinct     e.employee empno,     ch.perend periodend,     ch.prpoststat upempl e     inner join upchkh ch          on e.employee = ch.employee      ch.perend = @periodend 

here sqldataadapter call:

executesqlcommandscript(string sqlscript, list<sqlparams> sqlparams) {     . . . (setup sqlconnection info)      using (sqlconnection _conn = new sqlconnection(connectionstring))     {         using (sqlcommand _cmd = new sqlcommand())         {             _cmd.commandtext = sqlscript;             _cmd.connection = _conn;             _cmd.connection.open();              // add sqlparameters sql command             if (sqlparams != null)             {                 _cmd.parameters.addrange(sqlparams.toarray());             }              using (sqldataadapter _sqldataadapter = new sqldataadapter(_cmd))             {                try                {                     // save table info results object                     dataset _dataset = new dataset();                     _sqldataadapter.fill(_dataset);                       sqlresult _result = new sqlresult();                     _result.dataset = _dataset;                     _result.tablecount = _dataset.tables.count;                      this.results.add(_result);                 }             }         }     } } 

using sql server profiler can see query passed sql is:

exec sp_executesql n' select distinct     e.employee empno,     ch.perend periodend,     ch.prpoststat upempl e     inner join upchkh ch          on e.employee = ch.employee      ch.perend = @periodend  ',n'@periodend nvarchar(8)',@periodend=n'20161101' 

if run directly in sql these reults:

however, results of datatable created _sqldataadapter is:

is there way force sqldataadapter use data type in results? or possible sql indeed returning datetime object instead of decimal (the periodend column defined in sql decimal(9,0))? if there reason and/or way prevent it?

try , add column type explicitly when creating dataset , adding datacolumn of type decimal datatable. guess since not explicitly specifying column type, .net deriving value.