C# and MySql Inserting Data Error -

i have problem in application developing.

i insert 4 data fieldslets call them ("age", "gender" , "name", "tel") in mysql database. 99% of time work 100% once in while odd.

row 1 have age , gender, "null" , "null" , row 2 have "null" , "null" , name , tel insert 1 line of data 2 rows.

below sample of code:

string constring = configurationmanager.connectionstrings["server"].connectionstring;             string query = "insert db.table (name , surname , id , tel)  values('" + this.textbox1.text + "' , '" + this.textbox2.text + "'  ,  '" + this.textbox6.text + "'  , '" + this.textbox4.text + "');";             mysqlconnection condatabase = new mysqlconnection(constring);             mysqlcommand cmddatabase = new mysqlcommand(query, condatabase);             mysqldatareader myreader;             condatabase.open();             try             {                   myreader = cmddatabase.executereader();                  while (myreader.read())                 {                  }                 condatabase.close();             }             catch (exception ex)             {                 messagebox.show(ex.message);             }             messagebox.show("cleint details has been added system");         } 

if can think of reason please help. did check environment (network connection etc.) fine.

it possible there values in text box affecting insert statement. better if used parameterised statements. e.g.:

string query = "insert db.table (name , surname , id , tel) values(@param1, @param2 , @param3  , @param4);";  mysqlconnection condatabase = new mysqlconnection(constring); mysqlcommand cmddatabase = new mysqlcommand(query, condatabase);  //add paramter values cmddatabase.parameters.addwithvalue("@param1", this.textbox1.text); cmddatabase.parameters.addwithvalue("@param2", this.textbox2.text); cmddatabase.parameters.addwithvalue("@param3", this.textbox6.text); cmddatabase.parameters.addwithvalue("@param4", this.textbox4.text);