How to avoid duplicate values going into the mysql table using php

Question

I have a variable $Title and contains the following:

$Title = aa, bb, cc, dd, ee, ff
$Pubdate = aa, bb, cc, dd, ee, ff
$Link = aa, bb, cc, dd, ee, ff

and I insert it into the table with the column name Title. (Nice simple so far)

However, the variable updates every 1 hour and for example may turn into this.

$Title = cc, dd, ee, ff, gg, hh
$Pubdate = cc, dd, ee, ff, gg, hh
$Link = cc, dd, ee, ff, gg, hh

FYI: the values like "aa" of $Title are not the same value with "aa" of $Pubdate or of $Link, but are linked to each other
I was wondering if there is a way to avoid duplicate values going into the table again, so that only 'gg' and 'hh' goes in.
I know you can do it easily if you specify one value, like this

INSERT IGNORE INTO ytable (Title, Pubdate, Link) VALUES ('aa','aa');

but when it updates, I'm not sure what the next value will be so I need your help.

you can set title column as your primary key which wont allow to repeat the values present already. — Domain
– Domain, Commented Aug 18, 2015 at 5:37

Vegard Larsen · Accepted Answer · 2015-08-17 08:55:11Z

2

You need to set a UNIQUE constraint on your database. That way, whenever you try to insert a row with the same value, it will be rejected by the database.

Here is a sample query, which you may have to adapt:

ALTER TABLE foo MODIFY Title VARCHAR(255) NOT NULL UNIQUE;

This ensures that the database will protest when you attempt to insert a row without a unique Title value.

answered Aug 17, 2015 at 8:55

Vegard Larsen

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