C#實現(xiàn)定義一套中間SQL可以跨庫執(zhí)行的SQL語句(案例詳解)

更新時間：2022年07月04日 14:35:46 作者：tansar

這篇文章主要介紹了C#實現(xiàn)定義一套中間SQL可以跨庫執(zhí)行的SQL語句，主要包括hisql查詢樣例、group by查詢、鏈?zhǔn)讲樵兗癶isql語句和鏈?zhǔn)讲樵兓煊玫膕ql語句，本文給大家介紹的非常詳細(xì)，對大家的學(xué)習(xí)或工作具有一定的參考借鑒價值,需要的朋友可以參考下

目前數(shù)據(jù)的種類非常多，每種數(shù)據(jù)都支持sql語句，但是大家發(fā)現(xiàn)沒有每種數(shù)據(jù)的SQL都有自己的語法特性，都是SQL語句都沒有一個特定的語法標(biāo)準(zhǔn)，導(dǎo)致開發(fā)人員在開發(fā)的過程中無法任意選庫（如果用自己不熟的庫都會要學(xué)習(xí)一遍SQL語法），主要是學(xué)習(xí)成本太高

那么有沒有一種工具能夠統(tǒng)一下sql語法規(guī)則，只要學(xué)一種sql語句就可以跨庫執(zhí)行，讓開發(fā)人員不用學(xué)習(xí)每種庫的SQL語句呢？

下面就給大家介紹一款開源工具 hisql源碼 hisql介紹

hisql查詢樣例

單表查詢

根據(jù)hisql語句通過ToSql()方法生成目標(biāo)sql的原生sql

var _sql = sqlClient.HiSql("select * from HTest01 where  CreateTime>='2022-02-17 09:27:50' and CreateTime<='2022-03-22 09:27:50'").ToSql();

hisql生成的sqlserver 的sql 如下的所示

select  [htest01].[SID],[htest01].[UName],[htest01].[Age],[htest01].[Salary],[htest01].[Descript],[htest01].[CreateTime],[htest01].[CreateName],[htest01].[ModiTime],[htest01].[ModiName] from [HTest01] as [HTest01]
 where [htest01].[CreateTime] >= '2022-02-17 09:27:50.000' and [htest01].[CreateTime] <= '2022-03-22 09:27:50.000'

hisql生成mysql的sql如下所示

select   `htest01`.`SID`,`htest01`.`UName`,`htest01`.`Age`,`htest01`.`Salary`,`htest01`.`Descript`,`htest01`.`CreateTime`,`htest01`.`CreateName`,`htest01`.`ModiTime`,`htest01`.`ModiName` from `htest01` as `htest01`
 where `htest01`.`CreateTime` >= '2022-02-17 09:27:50.000' and `htest01`.`CreateTime` <= '2022-03-22 09:27:50.000'

hisql生成postgresql 的sql下所示

select  "htest01"."SID","htest01"."UName","htest01"."Age","htest01"."Salary","htest01"."Descript","htest01"."CreateTime","htest01"."CreateName","htest01"."ModiTime","htest01"."ModiName" from "HTest01" as "htest01"
 where "htest01"."CreateTime" >= '2022-02-17 09:27:50.000' and "htest01"."CreateTime" <= '2022-03-22 09:27:50.000'

大家可以會問明明是 "select * from HTest01 where CreateTime>='2022-02-17 09:27:50' and CreateTime<='2022-03-22 09:27:50'" 用的 * 查詢生成的sql語句為什么會直接列出所有字段呢？熟HiSql的網(wǎng)友都應(yīng)該知道這里其實隱藏了一個功能就是用戶可以自定義字段排序在系統(tǒng)表 Hi_FieldModel 中可配置

group by查詢

hisql 默認(rèn)支持的常用函數(shù) max , count , min , sum , avg

string sql = sqlClient.HiSql("select FieldName, count(FieldName) as NAME_count,max(FieldType) as FieldType_max from Hi_FieldModel  group by FieldName").ToSql();

hisql生成的sqlserver 的sql 如下的所示

select  [hi_fieldmodel].[FieldName],count(*) as NAME_count,max([hi_fieldmodel].[FieldType]) as FieldType_max from [Hi_FieldModel] as [Hi_FieldModel]
 group by [hi_fieldmodel].[FieldName]

hisql生成mysql的sql如下所示

select   `hi_fieldmodel`.`FieldName`,count(*) as NAME_count,max(`hi_fieldmodel`.`FieldType`) as FieldType_max from `Hi_FieldModel` as `hi_fieldmodel`
 group by `hi_fieldmodel`.`FieldName`

hisql生成postgresql 的sql下所示

select  "hi_fieldmodel"."FieldName",count(*) as NAME_count,max("hi_fieldmodel"."FieldType") as FieldType_max from "Hi_FieldModel" as "hi_fieldmodel"
 group by "hi_fieldmodel"."FieldName"

having 查詢

上次有網(wǎng)友說having 實現(xiàn)起來很麻煩通過正則表達式解析很難實現(xiàn)，我只能說很多網(wǎng)友對正則表達式的理解還不是很深，正則表達式已經(jīng)應(yīng)用于種類型的編譯器中，下面就來演示一下Having

string sql_having = sqlClient.HiSql("select FieldName, count(FieldName) as NAME_count,max(FieldType) as FieldType_max from Hi_FieldModel  group by FieldName having count(FieldName) > 1").ToSql();

hisql生成的sqlserver 的sql 如下的所示

select  [hi_fieldmodel].[FieldName],count(*) as NAME_count,max([hi_fieldmodel].[FieldType]) as FieldType_max from [Hi_FieldModel] as [Hi_FieldModel]
 group by [hi_fieldmodel].[FieldName]
 having count(*) > 1

hisql生成mysql的sql如下所示

select   `hi_fieldmodel`.`FieldName`,count(*) as NAME_count,max(`hi_fieldmodel`.`FieldType`) as FieldType_max from `Hi_FieldModel` as `hi_fieldmodel`
 group by `hi_fieldmodel`.`FieldName`
 having count(*) > 1

hisql生成postgresql 的sql下所示

select  "hi_fieldmodel"."FieldName",count(*) as NAME_count,max("hi_fieldmodel"."FieldType") as FieldType_max from "Hi_FieldModel" as "hi_fieldmodel"
 group by "hi_fieldmodel"."FieldName"
 having count(*) > 1

join 多表查詢

hisql inner join 和 in 操作語法

var sql = sqlClient.HiSql("select a.tabname from hi_fieldmodel as a inner join Hi_TabModel as  b on a.tabname =b.tabname inner join Hi_TabModel as c on a.tabname=c.tabname where a.tabname='h_test'  and a.FieldType in (11,41,21)  ").ToSql();

hisql生成的sqlserver 的sql 如下的所示

select  [a].[TabName] from [Hi_FieldModel] as [a]
  inner join [Hi_TabModel] as [b] on [a].[TabName] = [b].[TabName] inner join [Hi_TabModel] as [c] on [a].[TabName] = [c].[TabName]
 where [a].[TabName] = 'h_test' and [a].[FieldType] in (11,41,21)

hisql生成mysql的sql如下所示

select   `a`.`TabName` from `Hi_FieldModel` as `a`
  inner join `Hi_TabModel` as `b` on `a`.`TabName` = `b`.`TabName` inner join `Hi_TabModel` as `c` on `a`.`TabName` = `c`.`TabName`
 where `a`.`TabName` = 'h_test' and `a`.`FieldType` in (11,41,21)

hisql生成postgresql 的sql下所示

select  "a"."TabName" from "Hi_FieldModel" as "a"
  inner join "Hi_TabModel" as "b" on "a"."TabName" = "b"."TabName" inner join "Hi_TabModel" as "c" on "a"."TabName" = "c"."TabName"
 where "a"."TabName" = 'h_test' and "a"."FieldType" in (11,41,21)

分頁

hisql 分頁只要在日常查詢上增加 Take() 每頁顯示多少數(shù)據(jù) Skip() 顯示第幾頁

var sql = sqlClient.HiSql("select a.tabname from hi_fieldmodel as a inner join Hi_TabModel as  b on a.tabname =b.tabname inner join Hi_TabModel as c on a.tabname=c.tabname where a.tabname='h_test'  and a.FieldType in (11,41,21)  ").Take(2).Skip(2).ToSql();

hisql生成的sqlserver 的sql 如下的所示

select  [TabName] from ( 
select ROW_NUMBER() OVER(Order by [a].[FieldType] ASC) AS _hi_rownum_, [a].[TabName] from [Hi_FieldModel] as [a]
  inner join [Hi_TabModel] as [b] on [a].[TabName] = [b].[TabName] inner join [Hi_TabModel] as [c] on [a].[TabName] = [c].[TabName]
 where [a].[TabName] = 'h_test' and [a].[FieldType] in (11,41,21)
) as hi_sql 
where hi_sql._hi_rownum_ BETWEEN (2-1)*2+1 and 2*2 order by  _hi_rownum_ asc

hisql生成mysql的sql如下所示

select `TabName` from ( 
select ROW_NUMBER() OVER(Order by `a`.`FieldType` ASC) AS `_hi_rownum_`, `a`.`TabName` from `Hi_FieldModel` as `a`
  inner join `Hi_TabModel` as `b` on `a`.`TabName` = `b`.`TabName` inner join `Hi_TabModel` as `c` on `a`.`TabName` = `c`.`TabName`
 where `a`.`TabName` = 'h_test' and `a`.`FieldType` in (11,41,21)
) as hi_sql 
 order by  `_hi_rownum_` asc
limit 2,2

hisql生成postgresql 的sql下所示

select "TabName" from ( 
select ROW_NUMBER() OVER(Order by "a"."FieldType" ASC) AS "_hi_rownum_", "a"."TabName" from "Hi_FieldModel" as "a"
  inner join "Hi_TabModel" as "b" on "a"."TabName" = "b"."TabName" inner join "Hi_TabModel" as "c" on "a"."TabName" = "c"."TabName"
 where "a"."TabName" = 'h_test' and "a"."FieldType" in (11,41,21)
) as hi_sql 
 order by  "_hi_rownum_" asc
limit 2 OFFSET 2

hisql 實現(xiàn)參數(shù)化

參數(shù)化可以有效的防注入，通過前端可以拼接的hisql語句通過參數(shù)化的方式傳入，這樣就解決了注入問題

string sql1= sqlClient.HiSql("select * from hi_tabmodel where tabname=@tabname ", new { TabName="H_test" ,FieldName="DID"}).ToSql();
    string sql2= sqlClient.HiSql("select * from hi_tabmodel where tabname=@tabname or TabType in( @TabType)", new { TabName="H_test" , TabType =new List<int> { 1,2,3,4} }).ToSql();
    string sql3 = sqlClient.HiSql("select * from hi_tabmodel where tabname=@tabname ", new Dictionary<string, object> { { "TabName", "H_test" } }).ToSql();

鏈?zhǔn)讲樵?/h2>

hisql除了提供hisql語法外還提供鏈?zhǔn)讲樵兎椒ㄈ缦滤?/p>

string sql = sqlClient.Query("Hi_FieldModel").As("A").Field("A.FieldType")
                .Join("Hi_TabModel").As("B").On(new HiSql.JoinOn() { { "A.TabName", "B.TabName" } })
                .Where("A.TabName='GD_UniqueCodeInfo'").Group(new GroupBy { { "A.FieldType" } })
                .Sort("A.FieldType asc", "A.TabName asc")
                .Take(2).Skip(2)
                .ToSql();

hisql語句和鏈?zhǔn)讲樵兓煊?/h2>

string sql = sqlClient.HiSql("select A.FieldType from Hi_FieldModel as A ")
                .Where("A.TabName='GD_UniqueCodeInfo'").Group(new GroupBy { { "A.FieldType" } })
                .Sort("A.FieldType asc", "A.TabName asc")
                .Take(2).Skip(2)
                .ToSql();

到此這篇關(guān)于C#實現(xiàn)定義一套中間SQL可以跨庫執(zhí)行的SQL語句的文章就介紹到這了,更多相關(guān)C#跨庫執(zhí)行SQL語句內(nèi)容請搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家！

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