Question

我正在尝试为矩阵生成一组行，但@xcolcount仅在循环中保持为零，而内循环执行它所需的行：

 Declare @xColCount int
 Declare @yRowCount int
 set @xColCount = 0
 set @yRowCount = 0

WHILE (@xColCount < @widthCol) 
BEGIN
    WHILE (@yRowCount < @heightRow)
    BEGIN
      -- do the insert
       INSERT     
         INTO Scenario.MapCell(Guid, Map, Col, ColAplha, Row)
       VALUES (newID(),  @mapGuid, @xColCount, 'A', @yRowCount)

       SET @yRowCount =  @yRowCount + 1
    END

    SET @xColCount =  @xColCount + 1
END

Answer 1

我认为你只需要在外部循环中将内部计数器重置为零 - 我将SET @yRowCount = 0移动到外部循环中：

DECLARE @xColCount int
DECLARE @yRowCount int

SET @xColCount = 0

WHILE (@xColCount < @widthCol) 
BEGIN
    SET @yRowCount = 0

    WHILE (@yRowCount < @heightRow)
    BEGIN
       -- do the insert
       INSERT INTO Scenario.MapCell(Guid, Map, Col, ColAplha, Row)
         VALUES(newID(), @mapGuid, @xColCount, 'A', @yRowCount)

       SET @yRowCount =  @yRowCount + 1
    END

    SET @xColCount =  @xColCount + 1
END

使用你的代码，一旦内部循环完成，@yRowCount处于@heightRow并且永远不会被重置 - 所以内部循环（以及INSERT语句）从未执行过。

Answer 2

如果您使用从零开始的numbers table，这将成为一个基于集合的语句

;WITH
  cX AS (SELECT Num AS xColCount FROM NumTable WHERE Num <= @widthCol),
  cY AS (SELECT Num AS yRow  Count FROM NumTable WHERE Num <= @heightRow)
INSERT Scenario.MapCell(Guid, Map, Col, ColAplha, Row)
SELECT
    @mapGuid, xColCount, 'A', yRowCount
FROM
    cX CROSS JOIN cY;

嵌套SQL存储过程而不循环

2 个答案: