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PO
 

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    <p>As you said, you cannot change it, but one easy solution for these cases are the Bitwise:</p> <p><a href="http://dev.mysql.com/doc/refman/5.0/en/bit-functions.html" rel="nofollow">http://dev.mysql.com/doc/refman/5.0/en/bit-functions.html</a></p> <p>eg:</p> <p>I set a number scheme for the status such as:<br> 1 = Prospective Customer<br> 2 = Cancelled Service<br> 4 = Pool Service<br> 8 = lawn mowing<br> 16 = window washing<br> 32 = tree trimming<br> 64 = house painting<br> 128 = mobile oil change </p> <p>With this scheme a customer who needs pool service (4) and window washing (16) will have a status of 20 (4 + 16). A prospect (1) who might be interested in a mobile oil change (128) would have a status of 129 (1+128). etc...</p> <p>Bitwise logic allows me to select customers who buy particular services based on their status value.</p> <pre><code>SELECT * FROM customers WHERE status &amp; 1 //returns all prospects) SELECT * FROM customers WHERE status &amp; 16 //returns all of my window washing customers even if they are cancelled SELECT * FROM customers WHERE (status &amp; 16) AND !(status &amp; 2) //returns all of my window washing customers but not the cancelled ones SELECT * FROM customers WHERE status &amp; 36 //returns all of my tree trimming AND pool service customers i.e. 32+4 SELECT * FROM customers WHERE status &amp; 10 //returns all cancelled lawn moving customers i.e. 2+8 SELECT * FROM customers WHERE (status &amp; 32) AND !(status &amp; 128) //returns all tree trimming customers who do not get a mobile oil change </code></pre>
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    1. POSQL select query with special modifications
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    1. USMichał Powaga
    1. USVancleiP
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    1. COTable with users very large, table with groups even large, so I don't think the best way is to update users(If I understand you right, you want to add new column where I should store status).
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      1. USLevchuk Ivan
    2. COIt's more a suggestion: for each group, create a field to save a byte number (1, 2, 4, 8 ..). Sum all "byte numbers" and save the result into the field `group_id` (instead of separated by ;) and use the selects above to retrieve the combinations as you wish.
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      1. USVancleiP
    3. COthe problem is that not only I use this table, and If I will change something it can bring a lot of problems.
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      1. USLevchuk Ivan
 

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