不循环时嵌套 SQL 存储过程

Question

我正在尝试为矩阵生成一组行，但 @xcolcount 只在循环中保持为零，而内部循环则执行所需的操作：

 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

我认为您只需要在外部循环内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

使用您的代码，一旦内部循环完成， @yRowCount 位于 @heightRow 并且从未重置 - 因此内部循环（以及 INSERT 语句）不再执行。

Answer 2

如果您使用从零开始的数字表，则这将成为一组基于声明

;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;