c# - Why am I getting 'Invalid attempt to read when no data is present' here? -

this question has answer here:

• invalid attempt read when no data present 6 answers

my stored procedure simple one-liner

create procedure checkiffinished         @pid uniqueidentifier    begin     select finished      partners      id = @pid    end   

and i'm calling c# code

using (sqlcommand cmd = new sqlcommand("checkiffinished", this._conn)) {     cmd.commandtype = commandtype.storedprocedure;     cmd.parameters.addwithvalue("@pid", pid);      this._conn.open();      using (sqldatareader datareader = cmd.executereader())     {         finished = datareader.getbyte(0) == 1 ? true : false;     }      this._conn.close(); } 

the column finished in partners table of type tinyint not null default 0

stack trace of error is

[invalidoperationexception: invalid attempt read when no data present.]
system.data.sqlclient.sqldatareader.checkdataisready(int32 columnindex, boolean allowpartiallyreadcolumn, boolean permitasync, string methodname) +6531242
system.data.sqlclient.sqldatareader.tryreadcolumn(int32 i, boolean settimeout, boolean allowpartiallyreadcolumn) +81
system.data.sqlclient.sqldatareader.readcolumn(int32 i, boolean settimeout, boolean allowpartiallyreadcolumn) +25
system.data.sqlclient.sqldatareader.getbyte(int32 i) +27
survey.models.surveydbmodel.checkiffinished(guid pid) +230

where going wrong here?

you forgot datareader.read().

until don't execute read() on data reader, data not available.