Structure
this blog introduce 3 ways using mybatis
- based on annotationed SQL and Query interfaces : suppored by MyBatis framework
- based on Query Wrapper : supported by MyBatis Plus framework
- MyBatis Plus provides a easier way to dynamically set condition and updated fields
- base on Query Condition : combined MyBatis Plus and Kotlin, so called MyBatis++
- MyBatis++ provides a more easier way to build complicated conditions
- and supports update values through an Example bean
MyBatis++ Controller Abilities
this controller present multiple ways to do CURD with MyBatis++
you can choose your favorite ones or those match your current project most comfortably
package
import
import
import
import
import
import
import
import
import
import .*
@RestController
class UserController {
@Autowired
private lateinit var userMapper: UserMapper
@GetMapping("/01")
fun selectAll(): String {
val userList = ()
return ()
}
@GetMapping("/02")
fun selectByName(): String {
val user = ("Jimmy")
return ().orEmpty()
}
@GetMapping("/03")
fun selectByCondition(): String {
val condition = condition { (User::name, "Jimmy") }
val users = (())
return ()
}
@GetMapping("/04")
fun insert(): String {
val user = User()
= ()
(user)
return ()
}
@GetMapping("/05")
fun insertOrUpdate(): String {
val user = User()
= "1"
= ()
(user)
return ()
}
@GetMapping("/06")
fun updateByCondition(): String {
val cond1 = condition { (User::id) }
val cond2 = condition { (User::name, "Jimmy") }
val cond3 = condition { (User::age, 15) }
val cond4 = condition {
(User::name, "Jimmy")
(User::age, 18)
}
val condition = cond1 and cond2 and cond3 attributes cond4
val count = (())
return ()
}
@GetMapping("/07")
fun updateByEntityAndCondition(): String {
val entity = User()
= "Updated"
= 36
val cond1 = condition { (User::id) }
val cond2 = condition { (User::name, "Jimmy") }
val cond3 = condition { (User::age, 35) }
val condition = cond1 and (cond2 or cond3)
val count = (entity, ())
return ()
}
@GetMapping("/08")
fun updateByExampleAndCondition(): String {
val example = UserExample()
= 18
val cond1 = condition { (User::id) }
val cond2 = condition { (User::name, "Jimmy") }
val cond3 = condition { (User::age, 35) }
val condition = cond1 and (cond2 or cond3) values example
val count = (())
return ()
}
@GetMapping("/09")
fun selectCrossTables(): String {
val userRoles = ()
return ()
}
}Configure Plugins and Repositories
pluginManagement {
repositories {
gradlePluginPortal()
google()
mavenCentral()
}
}
dependencyResolutionManagement {
repositoriesMode = RepositoriesMode.PREFER_SETTINGS
repositories {
gradlePluginPortal()
google()
mavenCentral()
}
}
buildscript {
repositories {
gradlePluginPortal()
google()
mavenCentral()
}
}
plugins {
id("") version "2.0.21" apply false
id("") version "2.0.21" apply false
id("") version "2.0.21" apply false
id("") version "3.4.1" apply false
}
include("spring-mybatis")Apply Plugins and Add Dependencies
plugins {
id("")
id("")
id("")
id("")
}
java {
toolchain {
languageVersion = (17)
}
}
dependencies {
val springBootVersion = "3.4.1"
val springCloudVersion = "4.2.0"
val springCloudAlibabaVersion = "2023.0.3.2"
// commons
api(".hellogoogle2000:kotlin-commons:1.0.19")
// kotlin
api(":kotlin-reflect:2.0.21")
// spring
api(":spring-boot-starter:$springBootVersion")
api(":spring-boot-starter-web:$springBootVersion")
api(":spring-cloud-starter-bootstrap:$springCloudVersion")
// mybatis
api(":quick-spring-boot-starter-mybatis-plus:2025.01.22")
}MyBatis++ Spring Properties
# service =10003 =mybatis =dev -properties=false # mybatis =root =123456789 =jdbc:mysql://localhost:3306/dev?characterEncoding=utf-8&serverTimezone=UTC
MyBatis++ Application
package
import
import
import
@SpringBootApplication
@MapperScan(basePackages = [""])
class MybatisApplication
fun main(args: Array<String>) {
runApplication<MybatisApplication>(*args)
}MyBatis++ Beans
package
import
import
class User {
@TableId(type = IdType.ASSIGN_UUID)
var id = ""
var name = ""
var age = 0
}package
class UserExample {
var id: String? = null
var name: String? = null
var age: Int? = null
}package
class UserRoleQueryResult {
var name = ""
var role = ""
}MyBatis++ Mapper
mapper sometimes called interface, service or repository in other projects
package
import
import
import
import
interface UserMapper : BaseMapper<User> {
@Select("select * from user")
fun selectAll(): MutableList<User>
@Select("select * from user where name = #{name}")
fun selectUserByName(name: String): User?
@Select(
"""
select
as name,
as role
from user left join role
on =
"""
)
fun selectUserRole(): List<UserRoleQueryResult>
}MyBatis++ Query Builder
this is the core component to build query condition and examples
difference between entity and example is :
entity will update all field, while example only update non-null fields
package
import
import
import .KProperty1
import
fun interface ConditionConfigurator<T : Any> {
fun configure(wrapper: KtUpdateWrapper<T>)
}
data class QueryCondition<T : Any>(
val configurator: ConditionConfigurator<T>
)
inline fun <reified T : Any> QueryCondition<T>.build(): KtUpdateWrapper<T> {
val wrapper = KtUpdateWrapper(T::)
(wrapper)
return wrapper
}
inline fun <reified T : Any> condition(configurator: ConditionConfigurator<T>): QueryCondition<T> {
return QueryCondition(configurator)
}
infix fun <T : Any> QueryCondition<T>.and(other: QueryCondition<T>): QueryCondition<T> {
val configurator = ConditionConfigurator {
(it)
{ (it) }
}
return QueryCondition(configurator)
}
infix fun <T : Any> QueryCondition<T>.or(other: QueryCondition<T>): QueryCondition<T> {
val configurator = ConditionConfigurator {
(it)
{ (it) }
}
return QueryCondition(configurator)
}
infix fun <T : Any> QueryCondition<T>.not(other: QueryCondition<T>): QueryCondition<T> {
val configurator = ConditionConfigurator {
(it)
{ (it) }
}
return QueryCondition(configurator)
}
infix fun <T : Any> QueryCondition<T>.attributes(other: QueryCondition<T>): QueryCondition<T> {
val configurator = ConditionConfigurator {
(it)
(it)
}
return QueryCondition(configurator)
}
inline infix fun <reified T : Any, reified S : Any> QueryCondition<T>.values(example: S): QueryCondition<T> {
val configurator = ConditionConfigurator { wrapper ->
(wrapper)
val properties = S::
{ propertyS ->
val value = (example)
{ it != null } ?: return@forEach
val property = T::()
{ it != null } ?: return@forEach
(property, value)
}
}
return QueryCondition(configurator)
}
inline fun <reified T : Any> KClass<T>.findPropertyByName(name: String): KProperty1<T, *>? {
return { == name }
}This is all about this article about Spring Boot Mybatis++ 2025. For more related Spring Boot Mybatis++ 2025, please search for my previous articles or continue browsing the related articles below. I hope everyone will support me in the future!