c# - SQL Update - Not updating multiple rows in a for loop -

i have datagridview(dgv) linked sqlite database. want update info on dgv. so, have context menu lets me change 1 column , update db well. want have ability select multiple rows , edit well. ex: if select 5 rows , change type alarms errors ; change reflected in dgv , when database , change isnt reflected. 1 row updated.

my code snippet below

foreach (datagridviewrow r in datagridview1.selectedrows)         {             sqlitetransaction sqlitetrans = connection.begintransaction();             sqlitecommand cmd = connection.createcommand();             messagebox.show(r.tostring());             if (r.cells["typedatagridviewtextboxcolumn"].value.tostring().contains("#") == false)             {                 r.cells["typedatagridviewtextboxcolumn"].value = r.cells["typedatagridviewtextboxcolumn"].value.tostring() + " # " + max;             }             else             {                 r.cells["typedatagridviewtextboxcolumn"].value = r.cells["typedatagridviewtextboxcolumn"].value.tostring().substring(0, r.cells["typedatagridviewtextboxcolumn"].value.tostring().indexof("#")) + "# " + max;             }             string querytext = "update logdatabase set type = \"" + r.cells["typedatagridviewtextboxcolumn"].value + "\" hashkey = \"" + r.cells["hashkeydatagridviewtextboxcolumn"].value.tostring() + "\"";             cmd.commandtext = querytext;             cmd.executenonquery();             sqlitetrans.commit();             } 

i dont have experience sql. so, im not sure if wrong how ive updated database!

what have edit make sure rows updated in db well?!

help appreciated.

edit: tried checking query before sent.

when try editing multiple rows in dgv without sorting dgv under column works , updates rows simultaneously... when try sort them based on "type" , edit rows, same query passed ! :| (hash key doesnt change)

its like, 1 row keeps moving list of rows , row r in loop.

edit 2: problem rows of dgv everytime sort dgv , try edit fields, queries have hashkey values different once selected. row ids changed after 1 update. looks dgv automatically sorts once 1 row updated !

is there way disable this???!

it looks weren't increasing max counter.

foreach (datagridviewrow row in datagridview1.selectedrows) { using (sqlitetransaction sqlitetrans = connection.begintransaction()) {     sqlitecommand cmd = connection.createcommand();     messagebox.show(row.tostring());      var txtvalue = row.cells["typedatagridviewtextboxcolumn"].value;     if (txtvalue.contains("#"))     {         txtvalue = string.format("{0} # {1}", txtvalue, max);     }else     {         txtvalue = txtvalue.substring(0, txtvalue.indexof("#")) + "# " + max.tostring();     }     string querytext = "update logdatabase set type = @type hashkey = @key";             //create sqlparameters here!     cmd.commandtext = querytext;     cmd.executenonquery();     sqlitetrans.commit();         max++; //you weren't increasing counter!! } }