There´s a strange behaviour in my code which I can´t explain... I have worked arround it but I´d like to know the reason of this behaviour. My Code: If dataset.Tables.Count > 0 Then Dim rows() As DataRow = dataset.Tables(0).Select("FileID = " + fileid.ToString) For Each row As DataRow In rows... the one and only table in dataset is: 18 1 1 testpara42 19 1 2 Para2 23 2 1 Para1 24 2 2 Para42 Where the colums are: ParamID - FileID - ParaPos - Paravalue. I want do filter it so that the only rows I get are the ones with the correct fileid... the result when the selection string is "FileID = 1" is an array with 2 rows... everything is fine... but the filter string "FileID = 2" will return 0 Rows... A filter like "FileID < 1" returns 2 Rows correctly. I really cant´t explain this od behaviour, maybe one of the community does. The Table does have more entries but the Filter string just works with the "FileID = 1" selection. Excuse my bad english. Please explain my mistake to me.