c# - Update Database from Dataset -

my goal update qty each sku. using sqldataadapter accomplish this. program runs fine. no result happens.

question: why no result happening? database remains unchanged.

code below

public static void updateinventoryfromamz(datatable datatable) {         int index = 0;         string connstring = system.configuration.configurationmanager.connectionstrings["myconnectionstring"].tostring();         dataset amzinventorydataset = new dataset("amzinvdataset");         amzinventorydataset.tables.add(datatable);          // each row - perform update //         using (sqlconnection connection = new sqlconnection(connstring))         {             sqldataadapter adapter = new sqldataadapter();              foreach (datarow row in amzinventorydataset.tables[index].rows)             {                 string sku = datatable.rows[index]["seller-sku"].tostring();                 string qty = datatable.rows[index]["quantity"].tostring();                 // create updatecommand.                 sqlcommand command = new sqlcommand(                      "update inventory set qty = @qty" +                      "where sku = @sku", connection);                 // add parameters updatecommand.                 command.parameters.add("@qty", sqldbtype.int, qty.length, qty);                 command.parameters.add("@sku", sqldbtype.varchar, sku.length, sku);                 adapter.updatecommand = command;                 adapter.update(amzinventorydataset.tables[index]);                      index++;             }         }     } 

when concatenating 2 sql strings, better add space @ end of first string or @ beginning of second string. gordon linoff pointed out sql statement incorrect. , setting parameters , values need change depending on type of parameters.

try below code, have use sqlcommand , executenonquery method update each row data

using (sqlconnection connection = new sqlconnection(connstring)) using (sqlcommand cmd = new sqlcommand("update inventory set qty = @qty sku = @sku", connection)) {     connection.open();     var paramqty=  cmd.parameters.add("@qty", sqldbtype.int);     var parasku = cmd.parameters.add("@sku", sqldbtype.varchar);     foreach (datarow row in amzinventorydataset.tables[0].rows)     {         parasku.value = row["seller-sku"].tostring();         paramqty.value = int.parse(row["quantity"].tostring());         cmd.executenonquery();     } }