帮助创建视图

Question

我的看法是：

CREATE VIEW `vista_global` AS SELECT TC.nombreCentro, TP.Profesores, TA.Alumnos 
FROM tbl_centros TC 
LEFT JOIN (

SELECT centro, COUNT(*) Profesores 
FROM tbl_profesores 
GROUP BY centro 
)TP ON TC.idCentro = TP.centro 
LEFT JOIN (

SELECT centro, COUNT(*) Alumnos 
FROM tbl_alumnos 
GROUP BY centro 
)TA ON TC.idCentro = TA.centro 

但这不是运行良好。你能帮我吗？

Answer 1

您不必使用子查询：

CREATE VIEW `vista_global` AS 
SELECT TC.nombreCentro, 
     COUNT(TP.centro) Profesores, 
     COUNT(TA.centro) Alumnos 
FROM tbl_centros TC 
LEFT JOIN tbl_profesores TP ON TC.idCentro = TP.centro 
LEFT JOIN tbl_alumnos TQ ON TC.idCentro = TA.centro 
GROUP BY TC.nombreCentro