c# - not able to load odbcdatareader to a datatable -

i using informix db, , trying data specific item , store in datatable.

i checked following:

1) connection string looks good

2) connection able open

3) used same connection string web.config on dataset creating table adapter , able retrieve record.

this code using:

var connectionstring = configurationmanager.connectionstrings["testdatatable"].connectionstring; odbcconnection con = new odbcconnection(connectionstring); //con.connectionstring = connectionstring; if (txtitem.text != hold_item) {     con.open();     odbccommand cmd = new odbccommand(@"select t_item,t_idsc,t_upct,                                         t_item_upc,t_ctyp,t_citg,                                         t_best,t_disp,t_mold,t_csel                                          informix.tsckcm907                                         t_item = " + stitem, con);      odbcdatareader myreader = cmd.executereader();     datatable testdt = new datatable();     testdt.load(myreader);     foreach (datarow row in testdt.rows)     {        lbldesc.text = row["t_idsc"].tostring();        spanish_item();        {            dropdownlist2.selectedindex = 1;            object stlanguage = 1;            hold_language = convert.tostring(stlanguage);            txtbestbefore.text = row["t_best"].tostring();            holdbest = convert.toint16(txtbestbefore.text);        }    }    myreader.close();    myreader.dispose();    cmd.dispose();    con.close();    con.dispose(); } 

in debug mode error occurs @ odbcdatareader line: error message:

an exception of type 'system.data.odbc.odbcexception'  occurred in system.data.dll not handled in user code  additional information: error [42000] [informix] [informix odbc driver][informix]a syntax error has  occurred. 

if informix odbc driver says: "a syntax error has occurred" have check sql statement:

"select t_item,...  informix.tsckcm907 t_item = " + stitem 

i think wrong stitem. don't know type , value is, if type kind of string or date may in wrong form. easiest way extract full sql statement (simply print before execution) , use database editor (for example db_access informix). make work in sql editor , transform stitem variable acceptable form (add quotes, escape internal quotes, escape special characters etc.)

i recommend use of preparedstatement separates query data. way not need worry stitem form. no quotes, no escaping, place holder in query string , value added separately.

i don't use c# see c# can work preapred statements unnamed parameters:

cmd.commandtext = "select ... ... t_item = ?"; cmd.parameters.add("@t_item", obdctype.varchar, 200).value = t_item; 

or named parameters:

cmd.commandtext = "select ... ... t_item = @t_item"; cmd.parameters.add("@t_item", obdctype.varchar, 200).value = t_item; 

i use unnamed parameters odbc informix driver can work such parameters have check c#.