How to avoid ibatisN+1 query
This article will give you a detailed explanation on how to avoid ibatisN+1 queries. The editor thinks it is very practical, so I share it with you for reference. I hope you can get something after reading this article.
Java code avoids ibatisN+1 queries
Multi-party:
Public class Employ {
Private int id
Private String enployName
Private int salary
Private Department department
Public Employ () {
}
Public int getId () {
Return id
}
Public void setId (int id) {
This.id = id
}
Public String getEnployName () {
Return enployName
}
Public void setEnployName (String enployName) {
This.enployName = enployName
}
Public int getSalary () {
Return salary
}
Public void setSalary (int salary) {
This.salary = salary
}
Public Department getDepartment () {
Return department
}
Public void setDepartment (Department department) {
This.department = department
}
}
One party:
Public class Department {
Private int did
Private String departmentName
Private Listemployees
Public int getDid () {
Return did
}
Public void setDid (int did) {
This.did = did
}
Public String getDepartmentName () {
Return departmentName
}
Public void setDepartmentName (String departmentName) {
This.departmentName = departmentName
}
Public ListgetEmployees () {
Return employees
}
Public void setEmployees (Listemployees) {
This.employees = employees
}
}
Multi-party:
Public class Employ {
Private int id
Private String enployName
Private int salary
Private Department department
Public Employ () {
}
Public int getId () {
Return id
}
Public void setId (int id) {
This.id = id
}
Public String getEnployName () {
Return enployName
}
Public void setEnployName (String enployName) {
This.enployName = enployName
}
Public int getSalary () {
Return salary
}
Public void setSalary (int salary) {
This.salary = salary
}
Public Department getDepartment () {
Return department
}
Public void setDepartment (Department department) {
This.department = department
}
}
One party:
Public class Department {
Private int did
Private String departmentName
Private Listemployees
Public int getDid () {
Return did
}
Public void setDid (int did) {
This.did = did
}
Public String getDepartmentName () {
Return departmentName
}
Public void setDepartmentName (String departmentName) {
This.departmentName = departmentName
}
Public ListgetEmployees () {
Return employees
}
Public void setEmployees (Listemployees) {
This.employees = employees
}
}
If you want to avoid ibatisN+1 queries while working on mapping files, you can refer to the following code.
Xml code avoids ibatisN+1 queries
Multi-party:
1.
two。
3.
4. PUBLIC "- / ibatis.apache.org//DTD SQL Map 2.0//EN"
5. "http://ibatis.apache.org/dtd/sql-map-2.dtd" >
6.
7. < sqlMap namespace= "Employ" >
8.
9.
10. < typeAlias alias= "Employ" type= "com.test.domain.Employ" / >
11.
12.
13. From a query, and the class properties. A result map isn't
14. Necessary if the columns (or aliases) match to the properties
15. Exactly. -- >
16. < resultMap id= "EmployResult" class= "Employ" >
17. < result property= "id" column= "id" / >
18. < result property= "enployName" column= "employ_name" / >
19. < result property= "salary" column= "salary" / >
20. < result property= "department.did" column= "did" / >
21. < result property= "department.departmentName" column= "department_name" / >
twenty-two。 < / resultMap >
23.
24.
25. < select id= "selectAllEmploy" resultMap= "EmployResult" >
twenty-six。
twenty-seven。 Select * from employees e, departments d where e.departmentid = d.did
twenty-eight。 ]] >
twenty-nine。 < / select >
thirty。
thirty-one。 Aliases to match the properties of the target result class. -- >
thirty-two。
thirty-three。
