SQL:如何用相同的值填充两个特定行之间的行？

Question

我需要在两个“AL”或两个“MX”之间用“-”填充/替换行，其中值“AL”或“MX”取决于“-”出现的位置。出于本示例的目的，我仅使用 2 个“uid”(实际上我有更多 uid)。此外，该表按 ASC 中的 uid 和 code_date 列排序

为了便于理解，我有这个表格:

但我想要这样的东西:

我正在使用 SQL Server 2008。有关如何实现此目标的任何建议???

我使用以下代码创建了该表:

DECLARE @Customers TABLE
    (uid bigint,
     code_date date,
     Value nchar(10)
    ) 

INSERT  INTO @Customers
VALUES  (1591, '2016-08-01', ''),
    (1591, '2016-08-02', ''),
    (1591, '2016-08-03', 'AL'),
    (1591, '2016-08-04', '-'),
    (1591, '2016-08-05', '-'),
    (1591, '2016-08-06', '-'),
    (1591, '2016-08-07', '-'),
    (1591, '2016-08-08', '-'),
    (1591, '2016-08-09', 'AL'),
    (1591, '2016-08-10', ''),
    (1591, '2016-08-11', 'AL'),
    (1591, '2016-08-12', ''),
    (1082, '2016-02-01', ''),
    (1082, '2016-02-02', ''),
    (1082, '2016-02-03', ''),
    (1082, '2016-02-04', ''),
    (1082, '2016-02-05', 'MX'),
    (1082, '2016-02-06', '-'),
    (1082, '2016-02-07', '-'),
    (1082, '2016-02-08', '-'),
    (1082, '2016-02-09', '-'),
    (1082, '2016-02-10', '-'),
    (1082, '2016-02-11', '-'),
    (1082, '2016-02-12', 'MX');

    SELECT * FROM @Customers ORDER BY uid, code_date ASC

Answer 1

/* Test Data & Table */
DECLARE @Customers TABLE
    (Dates datetime,
     Customer integer,
     Value integer) 

    INSERT  INTO @Customers
    VALUES  ('20100101', 1, 12),
        ('20100101', 2, NULL),
        ('20100101', 3, 32),
        ('20100101', 4, 42),
        ('20100101', 5, 15),
        ('20100102', 1, NULL),
        ('20100102', 2, NULL),
        ('20100102', 3, 39),
        ('20100102', 4, NULL),
        ('20100102', 5, 16),
        ('20100103', 1, 13),
        ('20100103', 2, 24),
        ('20100103', 3, NULL),
        ('20100103', 4, NULL),
        ('20100103', 5, 21),
        ('20100104', 1, 14),
        ('20100104', 2, NULL),
        ('20100104', 3, NULL),
        ('20100104', 4, 65),
        ('20100104', 5, 23) ;

/* CustCTE - This gives us a RowNum to allow us to build the recursive CTE CleanCust */
WITH    CustCTE
          AS (SELECT    Customer,
                        Value,
                        Dates,
                        ROW_NUMBER() OVER (PARTITION BY Customer ORDER BY Dates) RowNum
              FROM      @Customers),

/* CleanCust - A recursive CTE. This runs down the list of values for each customer, checking the Value column, if it is null it gets the previous non NULL value.*/
        CleanCust
          AS (SELECT    Customer,
                        ISNULL(Value, 0) Value, /* Ensure we start with no NULL values for each customer */
                        Dates,
                        RowNum
              FROM      CustCte cur
              WHERE     RowNum = 1
              UNION ALL
              SELECT    Curr.Customer,
                        ISNULL(Curr.Value, prev.Value) Value,
                        Curr.Dates,
                        Curr.RowNum
              FROM      CustCte curr
              INNER JOIN CleanCust prev ON curr.Customer = prev.Customer
                                           AND curr.RowNum = prev.RowNum + 1)

/* Update the base table using the result set from the recursive CTE */
    UPDATE trg
    SET Value = src.Value
    FROM    @Customers trg
    INNER JOIN CleanCust src ON trg.Customer = src.Customer
                                AND trg.Dates = src.Dates

/* Display the results */
SELECT * FROM @Customers