PHP Novice about the problem: first page Select all data, click on the condition after the condition select database data

PHP Novice Problem: First page Select all data, click on the condition after the condition select database data
You ask a question, I want to make a page, go in the first time load is all the database, and then click the menu, reload the original page, but pass a condition to the original query, load display filter by criteria data, how to do ah.
------to solve the idea----------------------

 
 $where = "where 1=1";
if (Isset ($_post[' seach '))
{
if (!empty ($_post[' name ')) $where. = "and Name= ' $_post[name]";
if (!empty ($_post[' age '))) $where. = "and age= ' $_post[age]";
}
$sql = "SELECT * from table {$where}";
Echo $sql;
?>

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