examples: mysql concat function columns alias sql example

mysql concat function columns alias sql example - concatenating two or more columns to a single and rename by sql alias

Before running this example please make a database hr which can be found: click here to garb the script

mysql-concat-function-columns-alias-sql-example.php

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  <h2>mysql concat function columns alias sql example - concatenating two or more columns to a single and rename by sql alias</h2>
  <pre>
   <?php
    /*
     -----------------------------------------------------------------------------------
     so we have a table named EMPLOYEES in the HR database and we would like to concate 
     FirstName, LastName columns to a single one and also want to rename column heading
     by using mysql concat() function along with sql alias
     -----------------------------------------------------------------------------------
    */
    $sql = "SELECT concat(FirstName, LastName) as EmployeeName FROM employees";
    /*
     ----------------------------------------------------------------------------------
     note that - CONCAT() function returns NULL if any of the given argument(s) is NULL.
     
     ALSO NOTE(my experience) ABOUT NULL:
     
     1. NULL IS A VALUE THAT IS UNAVAILABLE
     2. NULL IS A VALUE THAT IS UNASSIGNED
     3. NULL IS A VALUE THAT IS UNKNOWN
     4. NULL IS A VALUE THAT IS INAPPLICABLE
     5. NULL IS A VALUE THAT IS NOT EVEN EQUAL TO NULL
     6. NULL IS A VALUE THAT IS NOT EQUAL TO ZERO : ZERO IS A NUMBER
     7. NULL IS A VALUE THAT IS NOT EQUAL TO BLANK SPACE OR EMPTY STRING : SPACE IS A CHARACTER
     AND 8. COLUMNS OF ANY DATATYPE CAN CONTAIN NULL VALUE
     ----------------------------------------------------------------------------------
    */
    /*
     -------------------------------------------------------
     USING PHP YOU CAN DO THIS. 
     GET CONNECTION TO DATABASE BY USING : mysql_connect()
     SELECT DATABASE BY USING : mysql_select_db()
     THEN RUN THE QUERY
     -------------------------------------------------------
    */
    

    mysql_connect('localhost', 'root', 'root');
    mysql_select_db('hr');
    mysql_query($sql);
    
    /*
     ------------------------------------------------------------------------------
     TO RUN THE PHP CODE PROVIDE REAL DATA TO mysql_connect AND mysql_select_db()
     ------------------------------------------------------------------------------
    */
   ?>
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mysql concat function columns alias sql example - concatenating two or more columns to a single and rename by sql alias - output in the client

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mysql concat function columns alias sql example

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