C ＃ implementation defines a set of SQL statements that can be executed across databases in the middle of SQL (detailed explanation of the case)

Catalog

hisql Query sample

Single table query

group by Inquire about

having Inquire about

join Multi-table query

Pagination

hisql Realize parameterization

Chain query

hisql Statements and chained queries are mixed

At present, there are many kinds of data , Every kind of data supports sql sentence , But we found that there is no data of every kind SQL Each has its own grammatical characteristics , All are SQL Statements do not have a specific grammatical standard , As a result, developers cannot choose libraries arbitrarily in the process of development （ If you use a library you are not familiar with, you will have to learn it again SQL grammar ）, The main reason is that the learning cost is too high

Is there a tool that can unify sql Rule of grammar , Just learn one sql Statement can be executed across libraries , So that developers do not have to learn every kind of Library SQL Sentence? ？

Now let's introduce an open source tool  hisql Source code  hisql Introduce

hisql Query sample Single table query

according to hisql Statement passing ToSql() Method to generate the target sql The native 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 Generated sqlserver Of sql As shown below

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 Generate mysql Of sql As shown below

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 Generate postgresql Of sql Shown below

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'

You can ask Obviously  "select * from HTest01 where CreateTime>='2022-02-17 09:27:50' and CreateTime<='2022-03-22 09:27:50'"  With  *  Inquire about Generated sql Why does the statement list all fields directly ？ Ripe HiSql Netizens should know that a function hidden here is that users can customize the sorting of fields in the system table  Hi_FieldModel  Can be configured in

group by Inquire about

hisql Common functions supported by default  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 Generated sqlserver Of sql As shown below

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 Generate mysql Of sql As shown below

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 Generate postgresql Of sql Shown below

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 Inquire about

Last time, some netizens said having It's troublesome to implement, and it's difficult to implement regular expression parsing , I can only say that many netizens don't understand regular expressions very well , Regular expressions have been applied to various types of compilers , Let's demonstrate 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 Generated sqlserver Of sql As shown below

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 Generate mysql Of sql As shown below

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 Generate postgresql Of sql Shown below

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(*) > 1join Multi-table query

hisql inner join and in Operation grammar

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 Generated sqlserver Of sql As shown below

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 Generate mysql Of sql As shown below

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 Generate postgresql Of sql Shown below

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) Pagination

hisql Pagination Just add  Take()  How much data is displayed per page  Skip()  Show the page

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 Generated sqlserver Of sql As shown below

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 Generate mysql Of sql As shown below

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_` asclimit 2,2

hisql Generate postgresql Of sql Shown below

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_" asclimit 2 OFFSET 2hisql Realize parameterization

Parameterization can effectively prevent injection , It can be spliced through the front end hisql The statement is passed into , This solves the injection problem

string sql1= sqlClient.HiSql("select * from hi_tabmodel where [email protected] ", new { TabName="H_test" ,FieldName="DID"}).ToSql(); string sql2= sqlClient.HiSql("select * from hi_tabmodel where [email protected] 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 [email protected] ", new Dictionary<string, object> { { "TabName", "H_test" } }).ToSql(); Chain query

hisql In addition to providing hisql In addition to the syntax, the chain query method is also provided as follows

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 Statements and chained queries are mixed 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();

This is about C# Implementation defines a set of intermediate SQL Can be executed across libraries SQL That's all for the statement article , More about C# Cross database execution SQL Please search the previous articles of software development network or continue to browse the relevant articles below. I hope you will support software development network more in the future ！