Support JDBC driver for iSeries DB2

buildScripts/docker/docker-compose-db2.yml

@@ -0,0 +1,22 @@
+version: '3.3'
+
+services:
+  db2:
+    container_name: DB2
+    image: ibmcom/db2:latest
+    ports:
+      - "50000:50000"
+    # Hide console output of db2 image
+    logging:
+      driver: "none"
+    environment:
+      LICENSE: accept
+      DB2INSTANCE: "inst"
+      DB2INST1_PASSWORD: "yourStrong(!)Password"
+      DBNAME: "testdb"
+    volumes:
+      - db:/database
+    privileged: true
+volumes:
+  db:
+    external: false

buildSrc/src/main/kotlin/org/jetbrains/exposed/gradle/DBTestingPlugin.kt

@@ -67,13 +67,18 @@ class DBTestingPlugin : Plugin<Project> {
                 testRuntimeOnly("org.mariadb.jdbc", "mariadb-java-client", Versions.mariaDB)
             }
 
+            val db2 = register<DBTest>("db2Test", "db2") {
+                testRuntimeOnly("com.ibm.db2", "jcc", Versions.db2)
+            }
+
             named<Test>("test") {
                 delegatedTo(
                     h2,
                     sqlite,
                     mysql51,
                     postgres,
-                    postgresNG
+                    postgresNG,
+                    db2
                 )
             }
         }

buildSrc/src/main/kotlin/org/jetbrains/exposed/gradle/Versions.kt

@@ -18,6 +18,7 @@ object Versions {
     const val postgreNG = "0.8.9"
     const val sqlLite3 = "3.36.0.3"
     const val sqlserver = "8.4.1.jre8"
+    const val db2 = "11.5.7.0"
 
     /** Spring **/
     const val springFramework = "5.3.13"

exposed-core/src/main/kotlin/org/jetbrains/exposed/sql/Column.kt

@@ -4,6 +4,7 @@ import org.jetbrains.exposed.exceptions.throwUnsupportedException
 import org.jetbrains.exposed.sql.transactions.TransactionManager
 import org.jetbrains.exposed.sql.vendors.H2Dialect
 import org.jetbrains.exposed.sql.vendors.SQLiteDialect
+import org.jetbrains.exposed.sql.vendors.DB2Dialect
 import org.jetbrains.exposed.sql.vendors.currentDialect
 import org.jetbrains.exposed.sql.vendors.inProperCase
 import java.util.*
@@ -45,12 +46,13 @@ class Column<T>(
 
     private val isLastColumnInPK: Boolean get() = table.primaryKey?.columns?.last() == this
 
-    internal val isPrimaryConstraintWillBeDefined: Boolean get() = when {
-        currentDialect is SQLiteDialect && columnType.isAutoInc -> false
-        table.isCustomPKNameDefined() -> isLastColumnInPK
-        isOneColumnPK() -> false
-        else -> isLastColumnInPK
-    }
+    internal val isPrimaryConstraintWillBeDefined: Boolean
+        get() = when {
+            currentDialect is SQLiteDialect && columnType.isAutoInc -> false
+            table.isCustomPKNameDefined() -> isLastColumnInPK
+            isOneColumnPK() -> false
+            else -> isLastColumnInPK
+        }
 
     override fun createStatement(): List<String> {
         val alterTablePrefix = "ALTER TABLE ${TransactionManager.current().identity(table)} ADD"
@@ -113,11 +115,11 @@ class Column<T>(
         }
 
         if (columnType.nullable || (defaultValue != null && defaultValueFun == null && !currentDialect.isAllowedAsColumnDefault(defaultValue))) {
-            append(" NULL")
-        } else if (!isPKColumn || (currentDialect is SQLiteDialect && !isSQLiteAutoIncColumn)) {
+            if (currentDialect !is DB2Dialect) // in db2 columns are null by default - there is no NULL keyword
+                append(" NULL")
+        } else if (!isPKColumn || (currentDialect is DB2Dialect && !columnType.isAutoInc)|| (currentDialect is SQLiteDialect && !isSQLiteAutoIncColumn)) {
             append(" NOT NULL")
         }
-
         if (!modify && isOneColumnPK() && !isPrimaryConstraintWillBeDefined && !isSQLiteAutoIncColumn) {
             append(" PRIMARY KEY")
         }
@@ -131,7 +133,7 @@ class Column<T>(
         table = this.table,
         name = this.name,
         columnType = columnType
-    ).also{
+    ).also {
         it.foreignKey = this.foreignKey
         it.defaultValueFun = this.defaultValueFun
         it.dbDefaultValue = this.dbDefaultValue

exposed-core/src/main/kotlin/org/jetbrains/exposed/sql/Constraints.kt

@@ -1,6 +1,7 @@
 package org.jetbrains.exposed.sql
 
 import org.jetbrains.exposed.sql.transactions.TransactionManager
+import org.jetbrains.exposed.sql.vendors.DB2Dialect
 import org.jetbrains.exposed.sql.vendors.MysqlDialect
 import org.jetbrains.exposed.sql.vendors.OracleDialect
 import org.jetbrains.exposed.sql.vendors.currentDialect
@@ -118,10 +119,16 @@ data class ForeignKeyConstraint(
                 append(" ON DELETE $deleteRule")
             }
             if (updateRule != ReferenceOption.NO_ACTION) {
-                if (currentDialect is OracleDialect) {
-                    exposedLogger.warn("Oracle doesn't support FOREIGN KEY with ON UPDATE clause. Please check your $fromTableName table.")
-                } else {
-                    append(" ON UPDATE $updateRule")
+                when  {
+                    currentDialect is OracleDialect -> {
+                        exposedLogger.warn("Oracle doesn't support FOREIGN KEY with ON UPDATE clause. Please check your $fromTableName table.")
+                    }
+                    currentDialect is DB2Dialect && updateRule == ReferenceOption.CASCADE -> {
+                        exposedLogger.warn("DB2 doesn't support FOREIGN KEY with ON UPDATE clause. Please check your $fromTableName table.")
+                    }
+                    else -> {
+                        append(" ON UPDATE $updateRule")
+                    }
                 }
             }
         }

exposed-core/src/main/kotlin/org/jetbrains/exposed/sql/Database.kt

@@ -83,7 +83,9 @@ class Database private constructor(
             "jdbc:mariadb" to "org.mariadb.jdbc.Driver",
             "jdbc:oracle" to "oracle.jdbc.OracleDriver",
             "jdbc:sqlite" to "org.sqlite.JDBC",
-            "jdbc:sqlserver" to "com.microsoft.sqlserver.jdbc.SQLServerDriver"
+            "jdbc:sqlserver" to "com.microsoft.sqlserver.jdbc.SQLServerDriver",
+            "jdbc:as400" to "com.ibm.as400.access.AS400JDBCDriver",
+            "jdbc:db2" to "com.ibm.db2.jcc.DB2Driver"
         )
         private val dialectMapping = mutableMapOf(
             "jdbc:h2" to H2Dialect.dialectName,
@@ -93,7 +95,9 @@ class Database private constructor(
             "jdbc:mariadb" to MariaDBDialect.dialectName,
             "jdbc:oracle" to OracleDialect.dialectName,
             "jdbc:sqlite" to SQLiteDialect.dialectName,
-            "jdbc:sqlserver" to SQLServerDialect.dialectName
+            "jdbc:sqlserver" to SQLServerDialect.dialectName,
+            "jdbc:as400" to DB2Dialect.dialectName,
+            "jdbc:db2" to DB2Dialect.dialectName
         )
 
         init {
@@ -105,6 +109,7 @@ class Database private constructor(
             registerDialect(OracleDialect.dialectName) { OracleDialect() }
             registerDialect(SQLServerDialect.dialectName) { SQLServerDialect() }
             registerDialect(MariaDBDialect.dialectName) { MariaDBDialect() }
+            registerDialect(DB2Dialect.dialectName) { DB2Dialect() }
         }
 
         fun registerDialect(prefix: String, dialect: () -> DatabaseDialect) {

exposed-core/src/main/kotlin/org/jetbrains/exposed/sql/Query.kt

@@ -2,6 +2,7 @@ package org.jetbrains.exposed.sql
 
 import org.jetbrains.exposed.sql.statements.Statement
 import org.jetbrains.exposed.sql.statements.api.PreparedStatementApi
+import org.jetbrains.exposed.sql.vendors.DB2Dialect
 import org.jetbrains.exposed.sql.vendors.currentDialect
 import java.sql.ResultSet
 import java.util.*
@@ -119,6 +120,10 @@ open class Query(override var set: FieldSet, where: Op<Boolean>?) : AbstractQuer
                 set.source.describe(transaction, this)
             }
 
+            if (set.source == Table.Dual && currentDialect is DB2Dialect) {
+                append(" FROM SYSIBM.SYSDUMMY1 ")
+            }
+
             where?.let {
                 append(" WHERE ")
                 +it

exposed-core/src/main/kotlin/org/jetbrains/exposed/sql/Table.kt

@@ -6,10 +6,7 @@ import org.jetbrains.exposed.dao.id.IdTable
 import org.jetbrains.exposed.exceptions.DuplicateColumnException
 import org.jetbrains.exposed.sql.statements.api.ExposedBlob
 import org.jetbrains.exposed.sql.transactions.TransactionManager
-import org.jetbrains.exposed.sql.vendors.OracleDialect
-import org.jetbrains.exposed.sql.vendors.PostgreSQLDialect
-import org.jetbrains.exposed.sql.vendors.SQLiteDialect
-import org.jetbrains.exposed.sql.vendors.currentDialect
+import org.jetbrains.exposed.sql.vendors.*
 import org.jetbrains.exposed.sql.vendors.currentDialectIfAvailable
 import org.jetbrains.exposed.sql.vendors.inProperCase
 import java.math.BigDecimal
@@ -1068,7 +1065,7 @@ open class Table(name: String = "") : ColumnSet(), DdlAware {
                 it,
                 startWith = 1,
                 minValue = 1,
-                maxValue = Long.MAX_VALUE
+                maxValue = if (currentDialect is DB2Dialect) Int.MAX_VALUE.toLong() else Long.MAX_VALUE
             ).createStatement()
         }.orEmpty()
 

exposed-core/src/main/kotlin/org/jetbrains/exposed/sql/statements/InsertStatement.kt

@@ -147,12 +147,12 @@ open class InsertStatement<Key : Any>(val table: Table, val isIgnore: Boolean =
     override fun prepared(transaction: Transaction, sql: String): PreparedStatementApi = when {
         // https://github.com/pgjdbc/pgjdbc/issues/1168
         // Column names always escaped/quoted in RETURNING clause
-         autoIncColumns.isNotEmpty() && currentDialect is PostgreSQLDialect ->
+        autoIncColumns.isNotEmpty() && currentDialect is PostgreSQLDialect ->
             transaction.connection.prepareStatement(sql, true)
 
         autoIncColumns.isNotEmpty() ->
             // http://viralpatel.net/blogs/oracle-java-jdbc-get-primary-key-insert-sql/
-            transaction.connection.prepareStatement(sql, autoIncColumns.map { it.name.inProperCase() }.toTypedArray())
+            transaction.connection.prepareStatement(sql, autoIncColumns.map { transaction.identity(it) }.toTypedArray())
 
         else -> transaction.connection.prepareStatement(sql, false)
     }