Question

我不擅长sql，但是我必须在我的存储过程中为jqGrid做分页，它有很多记录。我的asp.net mvc3控制器代码如下，

[HttpPost]
    public JsonResult GetExtraPersons(int cId, long pId, JQGridSettings gridSettings)
    {
        List<ExtraPerson> extraPersons = new List<ExtraPerson>();            
        ExtraPersonViewModel extraPersonViewModel = new ExtraPersonViewModel();
        extraPersonViewModel.CampId = cId;
        extraPersonViewModel.ReferencePatientId = pId;

        extraPersons = ExtraPersonService.GetExtraPersons(extraPersonViewModel.CampId, extraPersonViewModel.ReferencePatientId);

        int pageIndex = gridSettings.pageIndex;
        int pageSize = gridSettings.pageSize;
        int totalRecords = extraPersons.Count;
        int totalPages = (int)Math.Ceiling((float)totalRecords / (float)pageSize);

        int startRow = (pageIndex - 1) * pageSize;
        int endRow = startRow + pageSize;

        var jsonData = new
        {
            total = totalPages,
            page = pageIndex,
            records = totalRecords,
            rows =
            (
              extraPersons.Select(e => new
              {
                  Id = e.ExtraPersonId,                
                  FirstName = e.FirstName,
                  LastName = e.LastName,
                  MobilePhone = e.MobileNumber,
                  Email = e.EmailId,
                  PersonalNumber = e.PersonNumber,
                  Diabetes = e.Diabetes, 
                  BloodPressure = e.BloodPressure,
              })
            ).ToArray()
        };
        return Json(jsonData);
    }

以及我在sql server 2008中的存储过程如下，

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE [dbo].[GetExtraPerson] 
(
@CampId INT,
@ReferencePatientId BIGINT
)


AS  

BEGIN  
SET NOCOUNT ON         

SELECT  

PERS.PersonId,  
PERS.FirstName,  
PERS.LastName,  
PERS.MobileNumber,
PERS.EmailId,
PERS.PersonNumber,
E.ExtraPersonId,
E.Diabetes,
E.BloodPressure

FROM  
ExtraPerson E  
INNER JOIN Person PERS  
ON PERS.PersonId=E.PersonId  



WHERE E.CampId=@CampId AND ReferencePatientId=@ReferencePatientId AND E.IsDeleted = 0
END

现在jqGrid正常工作，除了分页。例如：如果它有15条记录，第一页显示10条记录，剩下的是第二页，但我不能去。任何人都可以建议我，如何为jqgrid做分页？

Answer 1

有很多方法可以实现您需要的STORED PROCEDURE。例如，您可以在CTE SQL语句中使用ROW_NUMBER构造。

如果您使用SQL Server 2012，则可以在OFFSET之后使用FETCH和ORDER BY来实现分页（请参阅here）。在这种情况下，SQL语句看起来非常接近使用OFFSET和LIMIT的相应MySQL或PostgreSQL语句。顺便说一句，Microsoft Entity Framework使用Entity SQL Language具有紧密结构（SKIP和LIMIT）。如果您使用SQL Server 2012或更高版本，则可能首选OFFSET和FETCH。

因为您在问题中包含了SQL Server 2008标记，所以在我的回答中我不会使用新的SQL Server 2012结构。

另一个好方法是使用sp_executesql，它允许您将SQL语句构造为带参数的字符串。它允许重用执行计划，这对于获得最佳性能非常重要。该方法允许您扩展STORED PROCEDURE的代码以实现服务器端过滤（搜索）。

我看到需要在SQL语句中实现包含返回数据的ID（在您的情况下为PersonId）的分页。因此，我决定建议您使用SELECT TOP与LEFT OUTER JOIN结合使用的简化方式。

您STORED PROCEDURE dbo.GetExtraPerson可以有两个int类型的附加参数：@skip和@pageSize。如果@skip等于0，则STORED PROCEDURE可以执行

SELECT TOP (@pageSize) PERS.PersonId
    ,PERS.FirstName
    ,PERS.LastName
    ,PERS.MobileNumber
    ,PERS.EmailId
    ,PERS.PersonNumber
    ,E.ExtraPersonId
    ,E.Diabetes
    ,E.BloodPressure
FROM ExtraPerson E  
    INNER JOIN Person PERS ON PERS.PersonId=E.PersonId  
WHERE E.CampId=@CampId AND ReferencePatientId=@ReferencePatientId AND E.IsDeleted=0

如果@skip不等于0，则相应的SQL语句可以是以下

WITH GetAll AS (
    SELECT PERS.PersonId
        ,PERS.FirstName
        ,PERS.LastName
        ,PERS.MobileNumber
        ,PERS.EmailId
        ,PERS.PersonNumber
        ,E.ExtraPersonId
        ,E.Diabetes
        ,E.BloodPressure
    FROM ExtraPerson E  
        INNER JOIN Person PERS ON PERS.PersonId=E.PersonId  
    WHERE E.CampId=@CampId AND ReferencePatientId=@ReferencePatientId AND E.IsDeleted=0
),GetFirst AS (
    SELECT TOP (@skip) *
    FROM GetAll
    ORDER BY Name
),GetNext AS (
    SELECT TOP (@pageSize) a.*
    FROM GetAll AS a
        LEFT OUTER JOIN GetFirst AS f ON f.Id=a.Id
    WHERE f.Id IS NULL
    ORDER BY Name
)
SELECT * FROM GetNext

dbo.GetExtraPerson的完整代码可以是以下

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

ALTER PROCEDURE dbo.GetExtraPerson 
    @CampId int,
    @ReferencePatientId bigint,
    @skip int,
    @pageSize int
AS
BEGIN
    DECLARE @records int;
    SET NOCOUNT ON;

    SET @records = (SELECT COUNT(*)
                    FROM ExtraPerson E  
                        INNER JOIN Person PERS ON PERS.PersonId=E.PersonId  
                    WHERE E.CampId=@CampId
                        AND ReferencePatientId=@ReferencePatientId
                        AND E.IsDeleted=0);

    IF @skip <= 0
        SELECT TOP (@pageSize) PERS.PersonId
            ,PERS.FirstName
            ,PERS.LastName
            ,PERS.MobileNumber
            ,PERS.EmailId
            ,PERS.PersonNumber
            ,E.ExtraPersonId
            ,E.Diabetes
            ,E.BloodPressure
        FROM ExtraPerson E  
            INNER JOIN Person PERS ON PERS.PersonId=E.PersonId  
        WHERE E.CampId=@CampId AND ReferencePatientId=@ReferencePatientId
            AND E.IsDeleted=0
    ELSE
        WITH GetAll AS (
            SELECT PERS.PersonId
                ,PERS.FirstName
                ,PERS.LastName
                ,PERS.MobileNumber
                ,PERS.EmailId
                ,PERS.PersonNumber
                ,E.ExtraPersonId
                ,E.Diabetes
                ,E.BloodPressure
            FROM ExtraPerson E  
                INNER JOIN Person PERS ON PERS.PersonId=E.PersonId  
            WHERE E.CampId=@CampId AND ReferencePatientId=@ReferencePatientId
                AND E.IsDeleted=0
        ),GetFirst AS (
            SELECT TOP (@skip) *
            FROM GetAll
            ORDER BY Name
        ),GetNext AS (
            SELECT TOP (@pageSize) a.*
            FROM GetAll AS a
                LEFT OUTER JOIN GetFirst AS f ON f.Id=a.Id
            WHERE f.Id IS NULL
            ORDER BY Name
        )
        SELECT * FROM GetNext;

    RETURN @records;
END
GO

上述步骤另外返回记录总数，您可以使用它来指定totalRecords值。

如果您将上述代码与sp_executesql结合使用，则可以轻松修改代码以在所有ORDER BY语句中包含SELECT TOP，以便返回的值对应于请求的排序顺序jqGrid中的用户。

如何在存储过程中为jqGrid进行分页？

1 个答案: