Records samentellen

<?php
$select=mysql_query("SELECT * FROM blabal") or die(mysql_error());
$rec=mysql_fetch_assoc($select);
$totaal=$rec['1']+$rec['2']+$rec['3'];
?>

<?php
$select=mysql_query("SELECT * FROM blabal") or die(mysql_error());
$rec=mysql_fetch_assoc($select);
$totaal=$rec['1']+$rec['2']+$rec['3'];
?>

.    Waarden
+----------+
|  Waarde  |
+----------+
|  1       |
|  5       |
|  8       |
|  2       |
+----------+

.    Waarden
+----------+
|  Waarde  |
+----------+
|  1       |
|  5       |
|  8       |
|  2       |
+----------+

SELECT SUM(Waarde)
FROM Waarden

SELECT SUM(Waarde)
FROM Waarden

SELECT SUM(<veld>) FROM <tbl> WHERE <veld>=<waarde>;

SELECT SUM(<veld>) FROM <tbl> WHERE <veld>=<waarde>;