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Database Normalization: Database Normalization in PHP/MySQL/SQL

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The normalization process involves getting our data to conform to three progressive normal forms, and a higher level of normalization cannot be achieved until the previous levels have been achieved (there are actually five normal forms, but the last two are mainly academic and will not be discussed).

First Normal Form The First Normal Form (or 1NF) involves removal of redundant data from horizontal rows. We want to ensure that there is no duplication of data in a given row, and that every column stores the least amount of information possible (making the field atomic).

Second Normal Form Where the First Normal Form deals with redundancy of data across a horizontal row, Second Normal Form (or 2NF) deals with redundancy of data in vertical columns. As stated earlier, the normal forms are progressive, so to achieve Second Normal Form, your tables must already be in First Normal Form.

Third Normal Form I have a confession to make; I do not often use Third Normal Form. In Third Normal Form we are looking for data in our tables that is not fully dependent on the primary key, but dependent on another value in the table.

posted Oct 6, 2014 by Vrije Mani Upadhyay

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Retrieve values from one database server and store them in other database server using PHP

We can always fetch from one database and rewrite to another. here
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$db1 = mysql_connect("host","user","pwd")
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$res2 = mysql_query("query",$db2);

At this point you can only fetch records from you previous ResultSet,
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supply the link as because the link was overwritten by the new db.
so at this point the following script will fail

$res3 = mysql_query("query",$db1);

//this will failSo how to solve that?
take a look below.

$db1 = mysql_connect("host","user","pwd")
mysql_select_db("db1", $db1);
$res1 = mysql_query("query",$db1);
$db2 = mysql_connect("host","user","pwd", true)
mysql_select_db("db2", $db2);
$res2 = mysql_query("query",$db2);

So mysql_connect has another optional boolean parameter which
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$res3 = mysql_query("query",$db1);
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