Update Query Is Not Working In VB.NET With MS Access -

imports system.data.oledb

public class form1

this connection string

dim con new oledbconnection("provider=microsoft.ace.oledb.12.0;data source=|datadirectory|store.accdb")  private sub picturebox1_click(byval sender system.object, byval e system.eventargs) handles picturebox1.click     con.open()      dim cmd new oledbcommand("select        [qty other], [hqty pl3], [hqty pl5], [total qty] from(material)where        ([mat code] = @a)", con)       cmd.parameters.addwithvalue("@a", textbox1.text)     dim dr oledbdatareader = cmd.executereader     dim qtyotherm, hqtypl3m, hqtypl5m, totalqtym new double     dim qtyotherr, rqtypl3r, rqtypl5r, qtyr new double     dim totalqtyfinal new double      dim cmdins new oledbcommand("insert recept ([mat code], qty, rate, taxes, [rqty pl3], [rqty pl5], [rqty other]) values        (@b, @c, @d, @e, @f, @g, @h)", con)       cmdins.parameters.addwithvalue("@b", textbox1.text)     cmdins.parameters.addwithvalue("@c", textbox2.text)     cmdins.parameters.addwithvalue("@d", textbox10.text)     cmdins.parameters.addwithvalue("@e", textbox9.text)     cmdins.parameters.addwithvalue("@f", textbox3.text)     cmdins.parameters.addwithvalue("@g", textbox4.text)     cmdins.parameters.addwithvalue("@h", textbox5.text)     dim checkinsert new integer     checkinsert = cmdins.executenonquery 

this execute non query working properly

    if checkinsert > 0             if dr.hasrows               while dr.read                 qtyotherm = dr(0)                 hqtypl3m = dr(1)                 hqtypl5m = dr(2)                 totalqtym = dr(3)             end while 

the text box showing addition vale

            totalqtyfinal = totalqtym + textbox2.text             textbox15.text = totalqtyfinal                messagebox.show("chk text box value") 

problem starts here

            dim cmdupdate new oledbcommand("update material set [total qty] = @j  ([mat code] = @i)", con)               cmdupdate.parameters.addwithvalue("@i", textbox1.text)             cmdupdate.parameters.addwithvalue("@j", textbox15.text)             dim chkupdate new integer             chkupdate = cmdupdate.executenonquery               if chkupdate > 0                 messagebox.show("update done   :)  ") 

always else statement message shown

            else                 messagebox.show("fail update  :(")             end if                 messagebox.show("quer 1 , 2 executed")          else             messagebox.show("dr not working.")         end if     else         messagebox.show("insert query fail")     end if     con.close()  end sub 

end class

see this answer. oledbcommand not support named parameters. need add parameters in same order have them in within sql statement.

in update statement, have @j followed @i, , you're adding @i followed @j. oledbcommand sees ? followed ? in sql statement, , when add parameters, adds parameter 1 followed parameter 2.