I used Exposed for DB access in kotlin, so it's a memorandum. To check the operation, I set up a test DB with Docker and checked it.
I referred to the following for the environment construction of DOcker. ・ Introduction of WSL2 and Docker https://qiita.com/KoKeCross/items/a6365af2594a102a817b
・ WSL2 memory depletion measures https://qiita.com/yoichiwo7/items/e3e13b6fe2f32c4c6120
A SQL library written in Kotlin. https://github.com/JetBrains/Exposed
First, the docker-compose.yaml file for creating a DB with Docker.
version: '3'
services:
db:
image: postgres:12.3
ports:
- 5433:5432
environment:
POSTGRES_USER: admin
POSTGRES_PASSWORD: admin
POSTGRES_DB: test_db
Next is the table definition.
object Member : Table("member") {
val id = integer("member_id").autoIncrement().primaryKey()
val name = varchar("name", 50)
val age = integer("age")
}
Finally the main function.
import org.jetbrains.exposed.sql.*
import org.jetbrains.exposed.sql.transactions.transaction
import org.jetbrains.exposed.sql.SchemUtils.create
fun main() {
Database.connect("jdbc:postgresql://localhot:5433/test_db", "org.postgresql.Driver", "admin", "admin")
transaction {
addLogger(StdOutSqlLogger)
create(Member)
Member.insert {
it[id] = 1
it[name] = "abc"
it[age] = 20
}
Member.insert {
it[id] = 2
it[name] = "efd"
it[age] = 30
}
for(member in Member.selectAll()) {
println("${member[Member.id]}: ${member[Member.name]}: ${member[Member.age]}")
}
Member.update({Member.name eq "abc"}) {
it[name] = "AIUEO"
}
for(member in Member.selectAll()) {
println("${member[Member.id]}: ${member[Member.name]}: ${member[Member.age]}")
}
Member.deleteAll()
drop(Member)
}
}
It's a defeat, but for the time being, I was able to confirm that CRUD can be done.
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