mysql row_number code example

Example 1: mysql num rows

//number of rows retrieved from a query
<?php

$link = mysql_connect("localhost", "mysql_user", "mysql_password");
mysql_select_db("database", $link);

$result = mysql_query("SELECT * FROM table1", $link);
$num_rows = mysql_num_rows($result);

echo "$num_rows Rows\n";

?>

Example 2: mysql row_number() example

SET @row_number = 0; 
SELECT 
    (@row_number:=@row_number + 1) AS num, 
    firstName, 
    lastName
FROM
    employees
ORDER BY firstName, lastName    
LIMIT 5;

Example 3: row number mysql

SELECT row_number() over ( order by firstName) RowNumberSqeuence,FirstName from rowNumberDemo
 order by FirstName;

Example 4: get row number in mysql 5.5

set @row_number := 0;

SELECT 
    @row_number:=CASE
        WHEN @customer_no = customerNumber 
			THEN @row_number + 1
        ELSE 1
    END AS num,
    @customer_no:=customerNumber customerNumber,
    paymentDate,
    amount
FROM
    payments
ORDER BY customerNumber;