SQL2005使用游标的实例(SBO中计算到期应收账款)

    我的SQL语言的查询做得并不好。但我可以用游标来实现之。实现之后才发现，无论多么复杂的查询，利用游标也都会更容易理解。虽然使用游标可能会牺牲一定的性能，但在硬件快速发展的今天，牺牲那么一点半点也未为不可。
    以下是我使用游标进行查询的一个实例，其中应该使用临时表的地方因为没有创建成功，只好使用事先创建好的表，显得此段代码有些不足，希望能给大家作抛砖引玉之用。
    这是一个在SBO中计算到期应收账款的应用，由于时间仓促，代码中没有太多注释，日后我会慢慢补上的。
代码：

 1 CREATE   PROCEDURE  TS_GetPayDay
 2 AS
 3 BEGIN  
 4      DECLARE   @DocNum   NVARCHAR ( 100 )       -- 订单号
 5      DECLARE   @NumAtCard   NVARCHAR ( 100 )    -- 合同号
 6      DECLARE   @CardName   NVARCHAR ( 100 )     -- 客户
 7      DECLARE   @PayTimes   INT                -- 总付款次数
 8      DECLARE   @PayTime   INT                 -- 付款次序
 9      DECLARE   @Prcnt   INT                   -- 付款百分比
10      DECLARE   @DocTotal  NUMERIC           -- 订单总额
11
12      DECLARE   @DocDate   DATETIME            -- 单据日期
13      DECLARE   @PayDay   DATETIME             -- 到期付款日期
14      DECLARE   @PayDay1   DATETIME            --
15      DECLARE   @Months   INT                  -- 间隔月份
16      DECLARE   @Days   INT                    -- 间隔天数
17      DECLARE   @CurRow   INT                  -- 当前行
18      DECLARE   @CurCtg   INT                  -- 当前付款条款
19
20      DELETE   FROM   [ TS_Payment ]
21      DELETE   FROM   [ TS_Payment1 ]
22      DELETE   FROM   [ TS_Payment2 ]
23
24      DECLARE  Rows_cursor  CURSOR
25      FOR
26          SELECT  T0.DocEntry
27          FROM  ORDR T0  ORDER   BY  T0.DocEntry
28      OPEN  Rows_cursor;
29      FETCH   NEXT   FROM  Rows_cursor  INTO   @CurRow ;
30      WHILE ( @@FETCH_STATUS <>- 1 )
31      BEGIN
32          IF ( @@FETCH_STATUS <>- 2 )
33          BEGIN
34              SET   @DocNum = ( SELECT  DocNum  FROM  ORDR  WHERE  DocEntry = @CurRow );
35              SET   @NumAtCard = ( SELECT  NumAtCard  FROM  ORDR  WHERE  DocEntry = @CurRow );
36              SET   @DocDate = ( SELECT  DocDate  FROM  ORDR  WHERE  DocEntry = @CurRow );
37              SET   @CardName = ( SELECT  CardName  FROM  ORDR  WHERE  DocEntry = @CurRow );
38              SET   @DocTotal = ( SELECT  DocTotal  FROM  ORDR  WHERE  DocEntry = @CurRow );
39
40              INSERT   INTO   [ TS_Payment1 ] (DocNum,NumAtCard,CardName,DocTotal)
41                  VALUES ( @DocNum , @NumAtCard , @CardName , @DocTotal )
42                 
43              SET   @PayTimes = ( SELECT  InstNum  FROM  OCTG  WHERE  GroupNum =
44                 ( SELECT  GroupNum  FROM  ORDR  WHERE  DocEntry = @CurRow ));
45              DECLARE  Ctg_cursor  CURSOR
46              FOR  
47                  SELECT  T1.IntsNo 
48                  FROM  CTG1 T1
49                  WHERE  T1.CTGCode = ( SELECT  GroupNum  FROM  ORDR  WHERE  DocEntry = @CurRow )
50              OPEN  Ctg_cursor;
51              FETCH   NEXT   FROM  Ctg_cursor  INTO   @CurCtg ;
52              WHILE ( @@FETCH_STATUS <>- 1 )
53              BEGIN
54                  IF ( @@FETCH_STATUS <>- 2 )
55                  BEGIN
56                      -- SELECT @CurCtg
57                      SET   @PayTime = ( SELECT  IntsNo  FROM  CTG1  WHERE  IntsNo = @CurCtg  
58                          AND  CTGCode
59                          = ( SELECT  GroupNum  FROM  ORDR  WHERE  DocEntry = @CurRow )); 
60                      SET   @Prcnt = ( SELECT  InstPrcnt  FROM  CTG1  WHERE  IntsNo = @CurCtg
61                          AND  CTGCode
62                          = ( SELECT  GroupNum  FROM  ORDR  WHERE  DocEntry = @CurRow )); 
63                      SET   @Months = ( SELECT  InstMonth  FROM  CTG1  WHERE  IntsNo = @CurCtg  
64                          AND  CTGCode
65                          = ( SELECT  GroupNum  FROM  ORDR  WHERE  DocEntry = @CurRow ));
66                      SET   @Days = ( SELECT  InstDays  FROM  CTG1  WHERE  IntsNo = @CurCtg  
67                          AND  CTGCode
68                          = ( SELECT  GroupNum  FROM  ORDR  WHERE  DocEntry = @CurRow ));
69
70                      SET   @PayDay1 = DATEADD ( MONTH , @Months , @DocDate );
71                      SET   @PayDay = DATEADD ( DAY , @Days , @PayDay1 );
72                      INSERT   INTO   [ TS_Payment2 ] (DocNum,NumAtCard,CardName,
73                         DocTotal,PayTimes,PayTime,Prcnt,PayDay)
74                          VALUES ( @DocNum , @NumAtCard , @CardName ,
75                          @DocTotal , @PayTimes , @PayTime , @Prcnt , @PayDay )
76                  END
77                  FETCH   NEXT   FROM  Ctg_cursor  INTO   @CurCtg ;
78              END
79              CLOSE  Ctg_cursor;
80              DEALLOCATE  Ctg_cursor;
81          END
82          FETCH   NEXT   FROM  Rows_cursor  INTO   @CurRow ;
83      END
84      CLOSE  Rows_cursor;
85      DEALLOCATE  Rows_cursor;
86
87      DELETE   FROM   [ TS_Payment1 ]   WHERE  DocNum  IN ( SELECT  DocNum  FROM   [ TS_Payment2 ] )
88
89      INSERT   INTO   [ TS_Payment ]
90      SELECT   *   FROM   [ TS_Payment1 ]
91          UNION   ALL  
92      SELECT   *   FROM   [ TS_Payment2 ]
93 END