ashrafzia Posted October 18, 2007 Share Posted October 18, 2007 I have the following table : ---------------------------------- Studnet_id | Reg_no | Std_name | etc.... ---------------------------------- - Initially all records are Null. - Student_id is Primary key. I want to read last record from the field Student_id i-e NULL and then add +1 to it to get new Student_id. This is the code: include "connection.php"; include "menu.php"; $tbname = "student_info"; $sql = "SELECT student_id FROM $tbname"; $result = @mysql_query($sql, $conn) or die (mysql_error()); if (!mysql_num_rows($result)){ $student_id++; } else { while ($row = mysql_fetch_array($result)){ $student_id = $row['student_id']; if ($student_id > 0) { $student_id++; } } } $form = "<body> <form action='PHP_SELF' method='post' enctype='multipart/form-data'> <table width='394' border='0' align='center' cellpadding='5' cellspacing='5'> <tr> <td width='135'>Studnet ID:</td> <td width='218'><input name='student_id' type='text' size='5' value=$student_id></td> </tr> <input type='image' name='register' src='images/register.gif'> etc...... </body>"; echo "$form"; if (isset($_POST['register_x'])){ $sql = "INSERT INTO $tbname (student_id, registration_no, student_name, father_name, programe, picture) VALUES ('$_POST[student_id]', '$_POST[registration_no]', '$_POST[student_name]', '$_POST[father_name]', '$_POST[programe]', '$_POST[picture]')"; $result = @mysql_query($sql, $conn) or die (mysql_error()); echo "Record Added Successfully....."; } Problems: Whenever a Record is added, everything goes fine but Student_id doesn't change. It remains the same. I want whenever someone enters a record, values should be added to database and then Student_id must be updated by reading last record/last value of Student_id and therefore incremented. The above code is working fine but there's a problem with it, and it's this : Whenever a record is added the Student_id doesn't change for the first time and when Register button is clicked again it gives a primary key error and then it's updated. I don't know what's the problem? I hope you got what i want to say.... If further any Question please ask. Quote Link to comment Share on other sites More sharing options...
Wes1890 Posted October 18, 2007 Share Posted October 18, 2007 First off, make sure your "STUDENT_ID" column in your MySQL Database is set to "auto_increment". Secondly, in your INSERT statement, where the student_id goes, just leave it blank. $sql = "INSERT INTO $tbname (student_id, registration_no, student_name, father_name, programe, picture) VALUES ('', '$_POST[registration_no]', '$_POST[student_name]', '$_POST[father_name]', '$_POST[programe]', '$_POST[picture]')"; Also I recommend validating your post information before putting it in your db... your just asking for someone to hack you... Quote Link to comment Share on other sites More sharing options...
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