Sql ，贷记或借记的金额越多，期初余额就越多。让我们看看为什么会发生这种情况，删除分组和聚合，检查我们真正总结的内容： SELECT vn.type, vn.name, v.date, vn.obal, v.credit, v.debit ; FROM v, vn ; WHERE v.name = vn.name

输出：

  TYPE     NAME DATE         OBAL CREDIT DEBIT
  bank     abc  06/01/2012    100      0    50
  bank     abc  06/02/2012    100      0    60
  bank     abc  06/03/2012    100      0    70
  bank     def  06/01/2012    200      0    50
  bank     def  06/02/2012    200      0    60
  bank     def  06/03/2012    200      0    70
  bank     ghi  06/01/2012    300      0    50
  bank     ghi  06/02/2012    300      0    60
  ledger   xyz  06/04/2012    400      0    50
  ledger   xyz  06/05/2012    400      0    60
  ledger   pqr  06/06/2012    500      0    50
  ledger   pqr  06/07/2012    500      0    60
  ledger   pqr  06/08/2012    500      0    70

你可以看到，比如说对于“abc”，OBal 100重复了3次，因为v中有3个条目。当它只有100的时候，加起来就是300

当您使用SUM（）或AVG（）之类的聚合时，应该先在没有连接的情况下进行聚合，然后再进行连接。您仍然可以使用联接进行聚合，只要联接结果是一对多的关系。如果上述结果集为：

  TYPE   NAME OBAL CREDIT DEBIT
  bank    abc  100      0   180
  bank    def  200      0   180
  bank    ghi  300      0   110
  ledger  xyz  400      0   110
  ledger  pqr  500      0   180

可以按类型（1对多的1边）求和（）

话虽如此，添加VFP支持子查询让我们编写一个解决方案：

Local sd,ed
sd = Date(2012,6,1)  && start date of transactions
ed = Date()          && current date as the end date...

Select vn.Type, Sum(vn.OBal - tmp.TotCd) As Opbal, Sum(tmp.Curbal) As Curbal ;
    FROM vn ;
    LEFT Join ;
       (Select v.Name, Sum(Iif(v.Date < sd, v.credit-v.debit, 0)) TotCd, ;
               SUM(Iif(Between(v.Date, sd, ed), v.credit-v.debit, 0)) Curbal ;
        FROM v ;
        GROUP By v.Name ) tmp On tmp.Name = vn.Name ;
    GROUP By vn.Type ;
    ORDER By vn.Type ;
    HAVING Sum(vn.OBal - tmp.TotCd + tmp.Curbal) != 0

---

您需要在

vn

表中按分组，然后将该结果加入到您的查询中。@Dems:我在想

按vn分组需要什么。键入
查询。有了按类型分组的obal，我认为你的答案很好。（顺便问一下，在Foxpro中，这个
在
ORDER By
之后是否有
有效语法？这让我很好奇）我假设
vn
的主键是
name
，根据描述。@ypercube-我的错，主键是
name
，而不是
type
。我想我刚刚看到了
name
我应该看到的
type
@ypercube：我已经很久没有使用FoxPro了，我也没有使用过FoxPro for Windows或Visual FoxPro，但是DOS版本在SELECT语句中的子句顺序方面有一定程度的自由度，也许该产品的后续版本保留了这种放纵的样本。设置，抱歉！它会产生一条错误消息：“函数名丢失”。“不幸的是，6年前的这个问题被推到了头版：（原因是这个问题急需一些解释，而设计也存在缺陷。不知道这些细节，就没有好的答案。1）永远不要依赖旧引擎行为来解决此错误。这是一个错误，已更正。依靠一个bug不是一个好办法。2） 要创建日期值，千万不要通过从字符串转换来创建。这取决于设置。最好使用solid date（）、datetime（）函数或严格的date\datetime文本。
SET ENGINEBEHAVIOR 90

CREATE CURSOR vn;
   ( date d, ;
     name c(25), ;
     type c(25), ;
     obal n(7) )

INSERT INTO vn VALUES ( CTOD( "5/20/2012" ), "person 1", "person type 1", 125 )
INSERT INTO vn VALUES ( CTOD( "5/20/2012" ), "person 2", "another type ", 2155 )

CREATE CURSOR v;
   ( date d, ;
     name c(25), ;
     desc c(50), ;
     debit n(7), ;
     credit n(7))

INSERT INTO V VALUES ( CTOD( "6/1/2012" ), "person 1", "description 1", 10, 32 )
INSERT INTO V VALUES ( CTOD( "6/2/2012" ), "person 1", "desc 2", 235, 123 )
INSERT INTO V VALUES ( CTOD( "6/3/2012" ), "person 1", "desc 3", 22, 4 )
INSERT INTO V VALUES ( CTOD( "6/4/2012" ), "person 1", "desc 4", 53, 36 )
INSERT INTO V VALUES ( CTOD( "6/5/2012" ), "person 1", "desc 5", 31, 3 )
INSERT INTO V VALUES ( CTOD( "6/1/2012" ), "person 2", "another 1", 43, 664 )
INSERT INTO V VALUES ( CTOD( "6/4/2012" ), "person 2", "more desc", 78, 332 )
INSERT INTO V VALUES ( CTOD( "6/6/2012" ), "person 2", "anything", 366, 854 )

sd = CTOD( "6/3/2012" )      && start date of transactions
ed = DATE()  && current date as the end date...

select;
      vn.name,;
      vn.type,;
      MAX( vn.obal ) as BalByNameOnly,;
      SUM( IIF( v.date < sd, v.credit-v.debit, 000000.00 )) OpBal, ;
      SUM( IIF( BETWEEN(v.date, sd, ed), v.credit - v.debit, 000000.00 )) CurBal ;
   FROM ;
      v,;
      vn ;
   WHERE ;
      v.name = vn.name;
   GROUP BY ;
      vn.Name,;
      vn.Type;
   INTO ;
      CURSOR C_JustByName READWRITE 

Name      Type            BalByNameOnly   OpBal   CurBal
person 1  person type 1       125         -90     -63 
person 2  another type       2155         621     742

SELECT ;
      JBN.type, ;
      JBN.BalByNameOnly - JBN.OpBal as OpBal,;
      JBN.CurBal ;
    FROM ;
       C_JustByName JBN ;
    GROUP BY ;
       vn.type ;
    ORDER BY ;
       vn.type ;
    HAVING ;
       OpBal + CurBal != 0;
    INTO ;
       CURSOR C_Final

SELECT vn.type, SUM(vn.obal + IIF(v.date < sd, v.credit-v.debit, 0)) OpBal, ;
    SUM(IIF(BETWEEN(v.date, sd, ed), v.credit-v.debit, 0)) CurBal ;
    FROM v, vn WHERE v.name = vn.name GROUP BY vn.type ;
    ORDER BY vn.type HAVING OpBal + CurBal != 0

CREATE CURSOR vn ( date d, name c(25), type c(25), obal n(7) )

INSERT INTO vn (date, name, type, obal) VALUES ( DATE(2012,5,20), "abc", "bank", 100 )
INSERT INTO vn (date, name, type, obal) VALUES ( DATE(2012,5,20), "def", "bank", 200 )
INSERT INTO vn (date, name, type, obal) VALUES ( DATE(2012,5,20), "ghi", "bank", 300 )
INSERT INTO vn (date, name, type, obal) VALUES ( DATE(2012,5,20), "xyz", "ledger", 400 )
INSERT INTO vn (date, name, type, obal) VALUES ( DATE(2012,5,20), "pqr", "ledger", 500 )

CREATE CURSOR v ( date d, name c(25), desc c(50), debit n(7), credit n(7))

INSERT INTO V (date,name,desc,debit,credit) VALUES ( DATE(2012,6,1), "abc", "description 1", 50, 0 )
INSERT INTO V (date,name,desc,debit,credit) VALUES ( DATE(2012,6,2), "abc", "description 1", 60, 0 )
INSERT INTO V (date,name,desc,debit,credit) VALUES ( DATE(2012,6,3), "abc", "description 1", 70, 0 )
INSERT INTO V (date,name,desc,debit,credit) VALUES ( DATE(2012,6,1), "def", "description 1", 50, 0 )
INSERT INTO V (date,name,desc,debit,credit) VALUES ( DATE(2012,6,2), "def", "description 1", 60, 0 )
INSERT INTO V (date,name,desc,debit,credit) VALUES ( DATE(2012,6,3), "def", "description 1", 70, 0 )
INSERT INTO V (date,name,desc,debit,credit) VALUES ( DATE(2012,6,1), "ghi", "description 1", 50, 0 )
INSERT INTO V (date,name,desc,debit,credit) VALUES ( DATE(2012,6,2), "ghi", "description 1", 60, 0 )
INSERT INTO V (date,name,desc,debit,credit) VALUES ( DATE(2012,6,4), "xyz", "description 1", 50, 0 )
INSERT INTO V (date,name,desc,debit,credit) VALUES ( DATE(2012,6,5), "xyz", "description 1", 60, 0 )
INSERT INTO V (date,name,desc,debit,credit) VALUES ( DATE(2012,6,6), "pqr", "description 1", 50, 0 )
INSERT INTO V (date,name,desc,debit,credit) VALUES ( DATE(2012,6,7), "pqr", "description 1", 60, 0 )
INSERT INTO V (date,name,desc,debit,credit) VALUES ( DATE(2012,6,8), "pqr", "description 1", 70, 0 )

SELECT vn.type, SUM(vn.obal + IIF(v.date < sd, v.credit-v.debit, 0)) OpBal, ;
    SUM(IIF(BETWEEN(v.date, sd, ed), v.credit-v.debit, 0)) CurBal ;
    FROM v, vn WHERE v.name = vn.name GROUP BY vn.type ;
    ORDER BY vn.type HAVING OpBal + CurBal != 0

TYPE    OPBAL   CURBAL
------- -----   ------
bank     1500     -470
ledger   2300     -290

SELECT vn.type, vn.name, v.date, vn.obal, v.credit, v.debit ;
    FROM v, vn ;
    WHERE v.name = vn.name

  TYPE     NAME DATE         OBAL CREDIT DEBIT
  bank     abc  06/01/2012    100      0    50
  bank     abc  06/02/2012    100      0    60
  bank     abc  06/03/2012    100      0    70
  bank     def  06/01/2012    200      0    50
  bank     def  06/02/2012    200      0    60
  bank     def  06/03/2012    200      0    70
  bank     ghi  06/01/2012    300      0    50
  bank     ghi  06/02/2012    300      0    60
  ledger   xyz  06/04/2012    400      0    50
  ledger   xyz  06/05/2012    400      0    60
  ledger   pqr  06/06/2012    500      0    50
  ledger   pqr  06/07/2012    500      0    60
  ledger   pqr  06/08/2012    500      0    70

  TYPE   NAME OBAL CREDIT DEBIT
  bank    abc  100      0   180
  bank    def  200      0   180
  bank    ghi  300      0   110
  ledger  xyz  400      0   110
  ledger  pqr  500      0   180

Local sd,ed
sd = Date(2012,6,1)  && start date of transactions
ed = Date()          && current date as the end date...

Select vn.Type, Sum(vn.OBal - tmp.TotCd) As Opbal, Sum(tmp.Curbal) As Curbal ;
    FROM vn ;
    LEFT Join ;
       (Select v.Name, Sum(Iif(v.Date < sd, v.credit-v.debit, 0)) TotCd, ;
               SUM(Iif(Between(v.Date, sd, ed), v.credit-v.debit, 0)) Curbal ;
        FROM v ;
        GROUP By v.Name ) tmp On tmp.Name = vn.Name ;
    GROUP By vn.Type ;
    ORDER By vn.Type ;
    HAVING Sum(vn.OBal - tmp.TotCd + tmp.Curbal) != 0

TYPE    OPBAL   CURBAL
------- -----   ------
bank      600     -470
ledger    900     -290