asp.net - Show error message on webpage if there trying to add duplicate value into database? -

asp.net - Show error message on webpage if there trying to add duplicate value into database? -

i have interface create new client both client code , client name insert client table. code not duplicate in table. want show error message on webpage if there duplicate code beingness typed client code area , submit. how this? next code, thanks!

protected void btnok_click(object sender, eventargs e) { sqlconnection conn = new sqlconnection(getconnectionstring()); sqlcommand cmd = new sqlcommand(); cmd.commandtype = commandtype.storedprocedure; cmd.connection = conn; cmd.commandtext = "dbo.insertcustomer"; cmd.parameters.addwithvalue("@ccode", txtcustomercode.text); cmd.parameters.addwithvalue("@cname", txtremark.text); seek { conn.open(); cmd.executenonquery(); string message = "new client created!"; system.text.stringbuilder sb = new system.text.stringbuilder(); sb.append("<script type = 'text/javascript'>"); sb.append("window.onload=function(){"); sb.append("alert('"); sb.append(message); sb.append("')};"); sb.append("</script>"); clientscript.registerclientscriptblock(this.gettype(), "alert", sb.tostring()); } grab (system.data.sqlclient.sqlexception ex) { string msg = "insert error:"; msg += ex.message; throw new exception(msg); } { conn.close(); conn.dispose(); } }

you set label message. like.

if(ex.message.tostring().contains("duplicate")) this.lblmessage.text = "code "+txtcustomercode.text+" taken." else this.lblmessage.text = msg;

not sure of exact text for. not rethrow exception.

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