SQL ROW_NUMBER（）問題與分頁

Question

我使用ROW_NUMBER()函數從數據庫表中獲取50個50項。
@From參數是從中開始抓取50行的行。 （第一次是51,101,151等1）
我將參數@CityId傳遞給存儲過程，如果數據庫中的前60行是cityId=1而cityId = 2在第61行，則此存儲過程不返回結果。
但是，如果我通過@From參數51而不是返回結果。 我在這里做錯了什么？

SELECT  RowConstrainedResult.*
FROM    ( SELECT    ROW_NUMBER() OVER 
( ORDER BY f.ItemCreatedOnDate DESC ) AS RowNum, 
f.*
FROM (
SELECT
      t.ItemIdId,
      t.ItemTypeId,
      t.CreatedOnDate as ItemCreatedOnDate,
      t.CityId as CityId
FROM   dbo.Items    as t
) f) AS RowConstrainedResult
WHERE   RowNum >= @From
    AND RowNum < @From + 50
    AND CityId = @CityId

Answer 1

在您的版本中， ROW_NUMBER()枚舉所有行。 將cityid的謂詞移動到最里面的選擇， ROW_NUMBER()只枚舉cityid = 2的行。

SELECT RowConstrainedResult.*
FROM (
     SELECT ROW_NUMBER() OVER (ORDER BY f.ItemCreatedOnDate DESC) AS RowNum, 
            f.*
     FROM (
          SELECT t.ItemIdId,
                 t.ItemTypeId,
                 t.CreatedOnDate as ItemCreatedOnDate,
                 t.CityId as CityId
          FROM dbo.Items AS t
          WHERE CityId = @CityId
          ) AS f
     ) AS RowConstrainedResult
WHERE RowNum >= @From AND 
      RowNum < @From + 50

Answer 2

我想你想要做的是在內部選擇查詢中過濾CityId，如下所示：

SELECT  RowConstrainedResult.*
FROM    ( SELECT    ROW_NUMBER() OVER 
( ORDER BY f.ItemCreatedOnDate DESC ) AS RowNum, 
f.*
FROM (
SELECT
      t.ItemIdId,
      t.ItemTypeId,
      t.CreatedOnDate as ItemCreatedOnDate,
      t.CityId as CityId
FROM   dbo.Items    as t
WHERE CityId = @CityId
) f) AS RowConstrainedResult
WHERE   RowNum >= @From
    AND RowNum < @From + 50