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Works great - can you help me understand why my query didn't process correctly?
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Also why would this work in terminal in mysql directly but not within a php script: -<br />
<br />

<pre><code class="code-1 nolinks" id="code-20-42110348-1"><span>UPDATE holding_amazon SET holding_amazon.catID = NULL WHERE holding_amazon.catID NOT IN (SELECT productCode.itemTitle FROM productCode)</span>
</code></pre>
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Scratch that I had a null value restriction in my table but I have a difference in the result sets between php and mysql.<br />
<br />
If I run the command from terminal I get 4 rows affected and yet if I run it from a php script I get 171 rows affected.<br />
<br />
Is it just me?
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<div>
productCode, holding_amazon creates a cross product - every record from the one table linked to every table of the other - so you will find a match for holding_amazon.catID &lt;&gt;&nbsp;productCode.itemTitle for every instance of catID<br />
<br />
The cross product is used to extract records that match on criteria - searching for records that don't match does not make sense as you will have every combination of non matching pairs represented.
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<blockquote>
Is it just me? 
</blockquote>
I have no idea - what does your script look like. Look for the obvious first - if the query works direct then you should get the same results in script.
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<div class="content wysiwyg-content">
Hi,<br />
<br />
I have a table (holding_amazon) which contains orders from Amazon. I want to check that the &quot;catID&quot;, the product SKU of the item, that was assigned to it when it was listed has no errors in the formatting by checking it's exists in another table (productCode) - this contains a list of approved SKU's. <br />
<br />
I've written the following query which I thought would check that the SKU exists in the table &quot;productCode&quot; under the column &quot;itemTitle&quot; and if it is that it doesn't to set the value of &quot;catID&quot; to empty so that an exception report can pick it up later in the process.<br />
<br />

<pre><code class="code-1 nolinks" id="code-10-29018921-1"><span>update productCode, holding_amazon set holding_amazon.catID ='' where holding_amazon.catID &lt;&gt; productCode.itemTitle</span>
</code></pre>
<br />
When I test the above query it sets all the values for &quot;catID&quot; to empty even though 90% exist in &quot;productCode&quot; table ... what am I doing wrong?
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Hi,

I have a table (holding_amazon) which contains orders from Amazon. I want to check that the "catID", the product SKU of the item, that was assigned to it when it was listed has no errors in the formatting by checking it's exists in another table (productCode) - this contains a list of approved SKU's. 

I've written the following query which I thought would check that the SKU exists in the table "productCode" under the column "itemTitle" and if it is that it doesn't to set the value of "catID" to empty so that an exception report can pick it up later in the process.

(CODE)

When I test the above query it sets all the values for "catID" to empty even though 90% exist in "productCode" table ... what am I doing wrong?

Update Set Column Query Not Working as Expected

PHP is a widely-used server-side scripting language especially suited for web development, powering tens of millions of sites from Facebook to personal WordPress blogs. PHP is often paired with the MySQL relational database, but includes support for most other mainstream databases. By utilizing different Server APIs, PHP can work on many different web servers as a server-side scripting language.

MySQL is an open source, relational database management system that runs as a server providing multi-user access to a number of databases. Acquired by Oracle in 2009, it is frequently used in combination with PHP installations, powering most of the WordPress installations.