Example Analysis of iBATIS.NET Multi-table query method
This article introduces the example analysis of iBATIS.NET multi-table query method, the content is very detailed, interested friends can refer to, hope to be helpful to you.
What is the method of iBATIS.NET multi-table query? Let's learn from examples step by step:
Create two tables Account and Degree, use Account_ID association, and need to find out all the records of the two tables.
First, modify the entity class by adding the following attributes:
Private Degree _ degree; public Degree Degree {get {return _ degree;} set {_ degree = value;}}
Then: modify the configuration file, which is also the most important part (the configuration file in PS:iBATIS.NET is really strong)
In the resultMaps section, add:
< resultMap id= "com2result" class= "Account" > < result property= "Id" column= "Account_ID" / > < result property= "FirstName" column= "Account_FirstName" / > < result property= "LastName" column= "Account_LastName" / > < result property= "EmailAddress" column= "Account_Email" nullValue= "no_email@provided.com" / > < result property= "Degree" resultMapping= "Account.Degree-result" / > < resultMap id= Degree-result "class=" Degree "> < result property=" Id "column=" Account_ID "/ > < result property=" DegreeName "column=" DegreeName "/ > < / resultMap >
The most important thing here is to use the resultMapping attribute, resultMapping= "Account.Degree-result", where Account is the namespace of the current configuration file:
< sqlMap namespace= "Account".
In the states section, add:
< select id= "GetCom2Tables" resultMap= "com2result" > select Accounts.*, Degree.* from Accounts,Degree where Accounts.Account_ID = Degree.Account_ID < / select >
In this way, you can write the sql you need as much as you like, and the performance is very good, so that there will not be a query statement of 1roomn in the third method.
Then, iBATIS.NET multi-table query method will be introduced to you here, I hope it will be helpful for you to understand iBATIS.NET multi-table query method.
This is the end of the sample analysis of the iBATIS.NET multi-table query method. I hope the above content can be helpful to you and learn more knowledge. If you think the article is good, you can share it for more people to see.
