Parse error in simple SQL UPDATE query

[Anon]

Im trying to implement a simple script that will enable me to modify an existing entry (being the student firstname) within my database based on the user_id field

When i execute within my browser i get:-

Parse error: parse error in c:\program files\apache group\apache\htdocs\sis\edit_student_entry.php on line 5

Can anybody help, i think there is an issue with my syntax, i can get this mysql query to excute within MS DOS command line but not through my PHP script.

---

<h2>Edit A Student</h2>

<form method=post action="edit_student_entry.php">

<b>Student ID:</b>
<input type=text size=5 name=student_id>
<br>
<b>First Name:</b>
<input type=text size=20 name=first_name>
<br>
<b>Last Name:</b>
<input type=text size=15 name=last_name>
<br>
<b>Module ID:</b>
<input type=text size=4 name=module_id>
<br>

<input type=submit name=submit value="Submit">
<input type=reset name=reset value="Clear">

---

This is the edit_student_entry script.

<?php include("dbconnect.php"); ?>
<?php

    $query = "update student_table set first_name="$first_name" where student_id="$student_id" "

    ;
    mysql_query($query);

?>
<h2>Edit Succesful</h2>
<h2><a href="index.html">Click to go back</a></h2>

---

To further myself after troubleshooting this, any tips on a query statement that will allow me to edit ANY field based on the 'student_id' entry?

All Help much appreciated.

[ace21]

"update student_table set first_name='$first_name' where student_id='$student_id'";

also you should put some error checking in

if(!mysql_query($query)
echo "Error";

Ace21

[Anon]

Ahh I See, it was the quotes afterall. Really appreciate the correction Ace. Any tips on being able to create a mass update based on any field entry, (user ID being the primary key).

_Adrian

[Anon]

I figured it out,

$query= "update student_table set first_name='$first_name', last_name='$last_name', module_id='$module_id' WHERE student_id='$student_id'"

Only problem is that i am unable to 'selectively' update a 'particular' field based on the student_id. i.e. (I just want to change the module and leave the remaining fields as they were). Is there some kind of OR command that will help me overcome this?

Cheers guys

-Adrian

[[deleted]]

What do you mean?
An update statement only contains the fields you want to update. if you don't want to update the stutend's first name, then leave that part out of the update query.

[Anon]

Hi Vince,

That is exactly my problem. If i leave a particular field in the form blank, a blank entry is made in the database. Lets assume that a student got married and i wanted to change her surname, with my current script i have to change every field asscoiated with her within the form otherwise her firstname would now be blank. I understand what you are saying, it looks as though i have to create a seperate UPDATE script for every field. arrgghhhh. Im sure PHP has powers to make life easier for me.

[Anon]

compare the fields with NULL and dont update if one is equal? :>

[[deleted]]

Allmost.

Compare the data that you got from the form with "" (empty string) and only add the field to the query if the var is not empty.

ala:

$sQuery = "UPDATE table SET ";
if ($field_from_form != "")
{
// var not empty, add to query
$sQuery = "field = ".$field_from_form.", ";
}

two things to keep in mind:
1. Parameters in the SET clause are seperated by a comma so each IF would add it's own comma (in case there are more parameters coming. Make sure that you somehow remove the last comma! (or you'll get "UPDATE table SET this=that, whoo=me, WHERE foo=bar")
(tip: add the clauses to an array and implode it with a comma)

2. The query must not be executed if it turns out that none of the fields were filled. (or you'll get "UPDATE table SET WHERE foo=bar")