Consulta en varias tablas.

[quimfv]

Código MySQL:

SELECT SUM(material) as material 
FROM (SELECT IFNULL(SUM(material),0) as material FROM  facturas WHERE realizacion BETWEEN '$FInicio' AND '$FFin'
UNION ALL
SELECT IFNULL(SUM(material),0) as material FROM  facturas_2011 WHERE realizacion BETWEEN '$FInicio' AND '$FFin'
UNION ALL
SELECT IFNULL(SUM(material),0) as material FROM  facturas_2012 WHERE realizacion BETWEEN '$FInicio' AND '$FFin')
 

o

Código MySQL:

SELECT SUM(material) as material 
FROM (SELECT realizacion,material FROM  facturas 
           UNION ALL
           SELECT realizacion,material FROM  facturas_2011 
           UNION ALL
          SELECT realizacion,material FROM  facturas_2012)
WHERE realizacion BETWEEN '$FInicio' AND '$FFin'