primary key-error

[ilikephp]

Hi,

I have a php form that is working fine, but when duplicate entries are entered I get this code on a new page:

"Duplicate entry '2010-111-3' for key 'PRIMARY'"

 

How can it be displayed on the same page using echo method?

 

Thank you,

[JonnoTheDev]

If a database field is a unique primary key it cannot accept duplicate entries. i.e You cannot have a users table with two users having an id (primary key) of 1. You must not attempt to insert records containing a key that is already in use. Use an auto-increment on the primary key, or generate the key before each insert.

[ilikephp]

Yeah I know that it can not be inserted in my database, But I need to let the user knows that

"There is duplicate key enter new information" using the if method

 

Thank you...

[Mchl]

Why are you using a date (?) as a primary key? You should not allow users to enter primary key by hand.

 

Use mysql_errno to catch this error and display proper message to user.

[JonnoTheDev]

Yeah I know that it can not be inserted in my database, But I need to let the user knows that

"There is duplicate key enter new information" using the if method

 

Thank you...

Then you must run a SELECT query prior to an INSERT.

 

$x = mysql_query("SELECT id FROM users WHERE name='Neil Johnson'");
if(mysql_num_rows($x)) {
print "You are already in my database";
}
else {
mysql_query("INSERT INTO users SET name='Neil Johnson'");
print "You have been added to my database";
}

[ilikephp]

usually if there is an error when filling a text box:

for example:

"Max. characters should be 5"

 

How can it be displayed using echo in top of the form?

[kenrbnsn]

For that you probably need to use AJAX.

 

Ken

[JonnoTheDev]

For that you probably need to use AJAX.

No. When the form is submitted, validate the data. Capture any errors in lets say an array. If there are errors simply re-display the same page with the errors next to the form or wherever you want to. Only when the form validates successfully should you save the data and redirect the user to a success screen.

 

This is basic stuff. I would strongly recommend going through a few tutorials if you are struggling.

http://www.google.co.uk/search?q=php+form+validation+tutorial