CAST to DECIMAL in MySQL
Ich versuche in MySQL auf Dezimal umzustellen:
CAST((COUNT(*) * 1.5) AS DECIMAL(2))
Ich versuche, die Anzahl der Zeilen in einer Tabelle (mal 1,5) in eine Gleitkommazahl mit zwei Ziffern nach dem Punkt umzuwandeln.
SQL-Code:
SELECT CONCAT(Guardian.title, ' ',
Guardian.forename, ' ',
Guardian.surname) AS 'Guardian Name',
COUNT(*) AS 'Number of Activities',
(COUNT(*) * 1.5) AS 'Cost'
FROM Schedule
INNER JOIN Child ON Schedule.child_id = Child.id
INNER JOIN Guardian ON Child.guardian = Guardian.id
GROUP BY Guardian
ORDER BY Guardian.surname, Guardian.forename ASC
Es entsteht ein Fehler:
#1064 - You have an error in your SQL syntax; check the manual that
corresponds to your MySQL server version for the right syntax to use
near 'CAST((COUNT(*) * 1.5) AS DECIMAL(12,2))' at line 1.
Ein weiterer Versuch, diese Besetzung funktioniert auch nicht:
SELECT CONCAT(Guardian.title, ' ',
Guardian.forename, ' ',
Guardian.surname) AS 'Guardian Name',
COUNT(*) AS 'Number of Activities',
CAST((COUNT(*) * 1.5) AS DECIMAL(8,2)) AS 'Cost'
FROM Schedule
INNER JOIN Child ON Schedule.child_id = Child.id
INNER JOIN Guardian ON Child.guardian = Guardian.id
GROUP BY Guardian
ORDER BY Guardian.surname, Guardian.forename ASC
Wie verwende ich MySQL, um von Integer zu Dezimal umzuwandeln?