Last Insert ID

Reads database-generated identity IDs from insert results.

Use cases

Use .withId() when one insert should return the database-generated identity primary key.

import com.kotlinorm.annotations.PrimaryKey
import com.kotlinorm.interfaces.KPojo

data class User(
    @PrimaryKey(identity = true)
    var id: Long? = null,
    var name: String? = null
) : KPojo

lastInsertId is available when the inserted KPojo uses @PrimaryKey(identity = true) and the primary key value is left null.

Read lastInsertId

Call .withId() on the insert that needs the generated ID.

val result = User(name = "Kronos")
    .insert()
    .withId()
    .execute()

val affectedRows = result.affectedRows
val lastInsertId = result.lastInsertId

execute() returns KronosOperationResult. affectedRows is the number of inserted rows, and lastInsertId is the generated identity value returned by the wrapper or the internal dialect fallback.

When no ID is returned

Kronos does not request a generated ID unless .withId() is present.

val result = User(name = "Kronos")
    .insert()
    .execute()

val lastInsertId = result.lastInsertId // null

If the primary key value is already set, the insert uses that value and lastInsertId stays empty.

val result = User(id = 1001, name = "Kronos")
    .insert()
    .withId()
    .execute()

val lastInsertId = result.lastInsertId // null

Dialect fallback SQL

The built-in KronosJdbcWrapper first reads JDBC generated keys during insert execution. If a wrapper cannot provide generated keys directly, Kronos uses the active dialect's follow-up SQL.

SELECT LAST_INSERT_ID()

SELECT LASTVAL()

SELECT last_insert_rowid()

SELECT SCOPE_IDENTITY()

SELECT MAX("ID") FROM "USER"