Java 从多个表中选择计数（*）

亲爱的朋友们，我需要从一个具有不同标准的表中获取计数（*）。我正在使用hibernate和spring。我正在使用下面的查询

"select  " +
            "(select count(*)  from enquiry  where business_id="+busid+")  AS allEnqCount,"+
    "(select count(*)  from enquiry where status='"+Constants.ENQ_FALLOWUP+"' and us.business_id="+busid+")  AS followupCount," +
    "(select count(*)  from enquiry where status='"+Constants.ENQ_SITE_VISIT+"'and us.business_id="+busid+")  AS siteVisitCount ," +
    "(select count(*)  from enquiry where status='"+Constants.ENQ_CUST_VISIT+"'and us.business_id="+busid+")  AS customerVisitCount," +
    "(select count(*)  from enquiry where status='"+Constants.ENQ_OFFICE_VISIT+"'and us.business_id="+busid+")  AS officevisitCount,"+
    "(select count(*)  from enquiry where status='"+Constants.ENQ_PENDING+"'and us.business_id="+busid+")  AS pending";

但这需要相当长的时间。你能告诉我有没有什么办法，我可以用最短的时间和一个选择条款来做这件事

提前感谢。

使用

案例

SELECT  SUM(CASE WHEN business_id = 'busid' THEN 1 END) allEnqCount,
        SUM(CASE WHEN status = 'ENQ_FALLOWUP' AND us.business_id = 'busid' THEN 1 END) followupCount,
        SUM(CASE WHEN status = 'ENQ_SITE_VISIT' AND us.business_id = 'busid' THEN 1 END) siteVisitCount,
        SUM(CASE WHEN status = 'ENQ_CUST_VISIT' AND us.business_id = 'busid' THEN 1 END) customerVisitCount,
        SUM(CASE WHEN status = 'ENQ_OFFICE_VISIT' AND us.business_id = 'busid' THEN 1 END) officevisitCount,
        SUM(CASE WHEN status = 'ENQ_PENDING' AND us.business_id = 'busid' THEN 1 END) pending
FROM    enquiry

---

只需更改满足您需要的值。

使用

分组方式

：

比如：

select 
      status,
      count(*) 
from enquiry 
where business_id = @busid 
group by status

---

谢谢JW。但所用的时间与以前相同。请尝试在状态和业务id上添加

INDEX

，例如，

ALTER TABLE inquiry ADD INDEX（business\u id，status）

，然后再次执行查询。除添加索引外，还应写入count（1）以代替count（*）。这里1是主键列的索引。@Andreas:谢谢，伙计，我肯定会尽我所能澄清这个问题，但在那之前，我会用你的概念来解释这个表中有多少行？