sqlserver 支持定位当前页,自定义排序的分页SQL(拒绝动态SQL)
1,场景:根据学生编号查询,返回该学生所在班级的所有学生。支持分页、自定义排序及结果集自动定位到查询条件的学生编号所在页。代码如下:
CREATE PROC [dbo].[Sp_testpagerandsorting] (@GroupID INT,
@CurrentId INT,
@TimeFrom DATETIME,
@TimeTo DATETIME,
@OrderBy CHAR(50),
@PageSize INT,
@CurrentPage INT)
AS
SET nocount ON
BEGIN
DECLARE @StartNumber INT,
@EndNumber INT,
@CurrentIdRowNumber INT,
@RecordCount INT,
@EndPageIndex INT
DECLARE @RowNumberTable TABLE (
rownumber INT IDENTITY (1, 1),
id INT )
--step 1: Build sort id list -------------------------------------------------------
INSERT INTO @RowNumberTable
(id)
SELECT sm.id AS id
FROM dbo.test sm WITH (nolock)
WHERE indate BETWEEN Coalesce(@TimeFrom, indate) AND
Coalesce(@TimeTo, indate)
AND sm.groupid = @GroupID
ORDER BY CASE
WHEN @OrderBy = 'InDate desc' THEN ( Row_number() OVER (ORDER BY indate DESC))
WHEN @OrderBy = 'InDate asc' THEN (Row_number() OVER (ORDER BY indate ASC))
WHEN @OrderBy = 'Id asc' THEN (Row_number() OVER (ORDER BY sm.id ASC))
WHEN @OrderBy = 'Id desc' THEN (Row_number() OVER (ORDER BY sm.id DESC))
WHEN @OrderBy = 'Name asc' THEN (Row_number() OVER (ORDER BY sm.name ASC))
WHEN @OrderBy = 'Name desc' THEN (Row_number() OVER (ORDER BY sm.name DESC) )
END
--step 2: Reset page index with current id -----------------------------------------
IF @CurrentIdNumber > 0
BEGIN
SELECT TOP 1 @CurrentIdRowNumber = rownumber
FROM @RowNumberTable
WHERE id = @CurrentIdNumber
IF @CurrentIdRowNumber > 0
BEGIN
IF @CurrentPage = 0
BEGIN
SET @CurrentPage = Ceiling(CAST(@CurrentIdRowNumber AS DECIMAL) / CAST (@PageSize AS DECIMAL))
END
END
END
ELSE
BEGIN
IF @CurrentPage = 0
BEGIN
SET @CurrentPage = 1
END
END
--step 3: Set recordCount -----------------------------------------
SELECT @RecordCount = COUNT(1)
FROM @RowNumberTable
--step 4: Calc startNumber & endNumber -----------------------------------------
SELECT @StartNumber = @PageSize * ( @CurrentPage - 1 ),
@EndNumber = @PageSize * ( @CurrentPage - 1 ) + @pageSize,
@EndPageIndex = Ceiling(CAST(@RecordCount AS DECIMAL) / CAST(@PageSize AS DECIMAL))
IF @CurrentPage = @EndPageIndex
BEGIN
SET @EndNumber = @RecordCount
END
--step 5: Get sorted id of current page -----------------------------------------
;WITH a
AS (SELECT TOP (@EndNumber - @StartNumber) id,
rownumber
FROM (SELECT TOP (@EndNumber) id,
rownumber
FROM @RowNumberTable) AS b
ORDER BY rownumber DESC)
--step 6: Return current page idList -------------------------------------------------------
SELECT [ID],
[GroupID] [Name],
[Address]
FROM dbo.test sm WITH(nolock)
INNER JOIN a
ON a.id = sm.id
ORDER BY a.rownumber
-- step 7:return current page & record count ----------------------------------
SELECT @CurrentPage AS currentpage,
@RecordCount AS recordcount
END
2,简单条件的,动态where语句(关于Like查询的动态where,建议使用笨办法做)
代码如下:
CREATE PROC [dbo].[Getstudentlistbycondition] @Name NVARCHAR(20),
@Class INT
AS
SET nocount ON
BEGIN
BEGIN
SELECT [Name],
[class]
FROM [testtable]
WHERE [Class] = CASE
WHEN @Class > 0 THEN @Class ELSE [Class] END
AND [name] = CASE
WHEN @Name '' THEN @Name ELSE [Name] END
END
END

掌握添加MySQL用戶的方法對於數據庫管理員和開發者至關重要,因為它確保數據庫的安全性和訪問控制。 1)使用CREATEUSER命令創建新用戶,2)通過GRANT命令分配權限,3)使用FLUSHPRIVILEGES確保權限生效,4)定期審計和清理用戶賬戶以維護性能和安全。

chosecharforfixed-lengthdata,varcharforvariable-lengthdata,andtextforlargetextfield.1)chariseffity forconsistent-lengthdatalikecodes.2)varcharsuitsvariable-lengthdatalikenames,ballancingflexibilitibility andperformance.3)

在MySQL中處理字符串數據類型和索引的最佳實踐包括:1)選擇合適的字符串類型,如CHAR用於固定長度,VARCHAR用於可變長度,TEXT用於大文本;2)謹慎索引,避免過度索引,針對常用查詢創建索引;3)使用前綴索引和全文索引優化長字符串搜索;4)定期監控和優化索引,保持索引小巧高效。通過這些方法,可以在讀取和寫入性能之間取得平衡,提升數據庫效率。

ToaddauserremotelytoMySQL,followthesesteps:1)ConnecttoMySQLasroot,2)Createanewuserwithremoteaccess,3)Grantnecessaryprivileges,and4)Flushprivileges.BecautiousofsecurityrisksbylimitingprivilegesandaccesstospecificIPs,ensuringstrongpasswords,andmonitori

tostorestringsefliceflicyInmySql,ChooSetherightDataTypeBasedyOrneOrneEds:1)USEcharforFixed-LengthStstringStringStringSlikeCountryCodes.2)UseVarcharforvariable-lengtthslikenames.3)USETEXTCONTENT.3)

選擇MySQL的BLOB和TEXT數據類型時,BLOB適合存儲二進制數據,TEXT適合存儲文本數據。 1)BLOB適用於圖片、音頻等二進制數據,2)TEXT適用於文章、評論等文本數據,選擇時需考慮數據性質和性能優化。

No,youshouldnotusetherootuserinMySQLforyourproduct.Instead,createspecificuserswithlimitedprivilegestoenhancesecurityandperformance:1)Createanewuserwithastrongpassword,2)Grantonlynecessarypermissionstothisuser,3)Regularlyreviewandupdateuserpermissions

mySqlStringDatatAtatPessHouldBechoseBasedondatActarActeristicsAndusecases:1)USEcharforFixed lengthStstringStringStringSlikeCountryCodes.2)usevarcharforvariable-lengtthslikeLikenames.3)usebarnionororvarinyorvarinyorvarybinarydatalgebenedaTalgeextocrabextrapon.4)


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