diff --git a/CommonCore/SQL/src/de/steamwar/sql/Referee.java b/CommonCore/SQL/src/de/steamwar/sql/Referee.java
deleted file mode 100644
index 3f909643..00000000
--- a/CommonCore/SQL/src/de/steamwar/sql/Referee.java
+++ /dev/null
@@ -1,56 +0,0 @@
-/*
- *   This file is a part of the SteamWar software.
- *
- *   Copyright (C) 2025 SteamWar.de-Serverteam
- *
- *   This program is free software: you can redistribute it and/or modify
- *   it under the terms of the GNU Affero General Public License as published by
- *   the Free Software Foundation, either version 3 of the License, or
- *   (at your option) any later version.
- *
- *   This program is distributed in the hope that it will be useful,
- *   but WITHOUT ANY WARRANTY; without even the implied warranty of
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- *   GNU Affero General Public License for more details.
- *
- *   You should have received a copy of the GNU Affero General Public License
- *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-
-package de.steamwar.sql;
-
-import de.steamwar.sql.internal.Field;
-import de.steamwar.sql.internal.SelectStatement;
-import de.steamwar.sql.internal.Statement;
-import de.steamwar.sql.internal.Table;
-import lombok.AllArgsConstructor;
-
-import java.util.Set;
-import java.util.stream.Collectors;
-
-@AllArgsConstructor
-public class Referee {
-
-    private static final Table<Referee> table = new Table<>(Referee.class);
-    private static final SelectStatement<Referee> byEvent = table.selectFields("eventID");
-
-    private static final Statement insert = table.insertAll();
-    private static final Statement delete = table.delete("eventReferee");
-
-    public static void add(int eventID, int userID) {
-        insert.update(eventID, userID);
-    }
-
-    public static void remove(int eventID, int userID) {
-        delete.update(eventID, userID);
-    }
-
-    public static Set<Integer> get(int eventID) {
-        return byEvent.listSelect(eventID).stream().map(referee -> referee.userID).collect(Collectors.toSet());
-    }
-
-    @Field(keys = {"eventReferee"})
-    private final int eventID;
-    @Field(keys = {"eventReferee"})
-    private final int userID;
-}
diff --git a/CommonCore/SQL/src/de/steamwar/sql/Referee.kt b/CommonCore/SQL/src/de/steamwar/sql/Referee.kt
new file mode 100644
index 00000000..e5df5bdd
--- /dev/null
+++ b/CommonCore/SQL/src/de/steamwar/sql/Referee.kt
@@ -0,0 +1,67 @@
+/*
+ *   This file is a part of the SteamWar software.
+ *
+ *   Copyright (C) 2025 SteamWar.de-Serverteam
+ *
+ *   This program is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU Affero General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *   GNU Affero General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Affero General Public License
+ *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.steamwar.sql
+
+import de.steamwar.sql.internal.useDb
+import org.jetbrains.exposed.v1.core.and
+import org.jetbrains.exposed.v1.core.dao.id.CompositeID
+import org.jetbrains.exposed.v1.core.dao.id.CompositeIdTable
+import org.jetbrains.exposed.v1.core.dao.id.EntityID
+import org.jetbrains.exposed.v1.core.eq
+import org.jetbrains.exposed.v1.dao.CompositeEntity
+import org.jetbrains.exposed.v1.dao.CompositeEntityClass
+import org.jetbrains.exposed.v1.jdbc.select
+
+object RefereeTable: CompositeIdTable("Referee") {
+    val eventId = reference("EventId", EventTable)
+    val userId = reference("UserId", SteamwarUserTable)
+
+    override val primaryKey = PrimaryKey(eventId, userId)
+
+    init {
+        addIdColumn(eventId)
+        addIdColumn(userId)
+    }
+}
+
+class Referee(id: EntityID<CompositeID>): CompositeEntity(id) {
+    companion object: CompositeEntityClass<Referee>(RefereeTable) {
+        @JvmStatic
+        fun add(eventId: Int, userId: Int) = useDb {
+            new {
+                this.eventID = eventId
+                this.userID = userId
+            }
+        }
+
+        @JvmStatic
+        fun remove(eventId: Int, userId: Int) = useDb {
+            find { (RefereeTable.eventId eq eventId) and (RefereeTable.userId eq userId) }.firstOrNull()?.delete()
+        }
+
+        @JvmStatic
+        fun get(event: Int) = useDb {
+            find { RefereeTable.eventId eq event }.map { it.userID }.toSet()
+        }
+    }
+
+    var eventID by RefereeTable.eventId.transform({ EntityID(it, EventTable) }, { it.value })
+    var userID by RefereeTable.userId.transform({ EntityID(it, SteamwarUserTable) }, { it.value })
+}
\ No newline at end of file
diff --git a/CommonCore/SQL/src/de/steamwar/sql/SWException.java b/CommonCore/SQL/src/de/steamwar/sql/SWException.java
deleted file mode 100644
index 945743f7..00000000
--- a/CommonCore/SQL/src/de/steamwar/sql/SWException.java
+++ /dev/null
@@ -1,68 +0,0 @@
-/*
- *   This file is a part of the SteamWar software.
- *
- *   Copyright (C) 2025 SteamWar.de-Serverteam
- *
- *   This program is free software: you can redistribute it and/or modify
- *   it under the terms of the GNU Affero General Public License as published by
- *   the Free Software Foundation, either version 3 of the License, or
- *   (at your option) any later version.
- *
- *   This program is distributed in the hope that it will be useful,
- *   but WITHOUT ANY WARRANTY; without even the implied warranty of
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- *   GNU Affero General Public License for more details.
- *
- *   You should have received a copy of the GNU Affero General Public License
- *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-
-package de.steamwar.sql;
-
-import de.steamwar.sql.internal.Field;
-import de.steamwar.sql.internal.Statement;
-import de.steamwar.sql.internal.Table;
-import lombok.AllArgsConstructor;
-
-import java.io.File;
-import java.sql.Timestamp;
-
-@AllArgsConstructor
-public class SWException {
-
-    public static void init() {
-        // force class initialialisation
-    }
-
-    private static final String CWD = System.getProperty("user.dir");
-    private static final String SERVER_NAME = new File(CWD).getName();
-
-    private static final Table<SWException> table = new Table<>(SWException.class, "Exception");
-    private static final Statement insert = table.insertFields(true, "server", "message", "stacktrace");
-
-    @Field(keys = {Table.PRIMARY}, autoincrement = true)
-    private final int id;
-    @Field(def = "CURRENT_TIMESTAMP")
-    private final Timestamp time;
-    @Field
-    private final String server;
-    @Field
-    private final String message;
-    @Field
-    private final String stacktrace;
-
-    public static void log(String message, String stacktrace){
-        insert.update(SERVER_NAME, generateMessage(message), stacktrace);
-    }
-
-    public static int logGetId(String message, String stacktrace) {
-        return insert.insertGetKey(SERVER_NAME, generateMessage(message), stacktrace);
-    }
-
-    private static String generateMessage(String message) {
-        StringBuilder msgBuilder = new StringBuilder(message);
-        SQLWrapper.impl.additionalExceptionMetadata(msgBuilder);
-        msgBuilder.append("\nCWD: ").append(CWD);
-        return msgBuilder.toString();
-    }
-}
diff --git a/CommonCore/SQL/src/de/steamwar/sql/SWException.kt b/CommonCore/SQL/src/de/steamwar/sql/SWException.kt
new file mode 100644
index 00000000..7c5dc33c
--- /dev/null
+++ b/CommonCore/SQL/src/de/steamwar/sql/SWException.kt
@@ -0,0 +1,69 @@
+/*
+ *   This file is a part of the SteamWar software.
+ *
+ *   Copyright (C) 2025 SteamWar.de-Serverteam
+ *
+ *   This program is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU Affero General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *   GNU Affero General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Affero General Public License
+ *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.steamwar.sql
+
+import de.steamwar.sql.internal.useDb
+import org.jetbrains.exposed.v1.core.dao.id.IntIdTable
+import org.jetbrains.exposed.v1.javatime.timestamp
+import org.jetbrains.exposed.v1.jdbc.insert
+import org.jetbrains.exposed.v1.jdbc.insertAndGetId
+import java.io.File
+import java.time.Instant
+
+object ExceptionTable: IntIdTable("Exception") {
+    val time = timestamp("Time").default(Instant.now())
+    val server = text("Server")
+    val message = text("Message")
+    val stackTrace = text("StackTrace")
+}
+
+class SWException {
+    companion object {
+        val cwd = System.getProperty("user.dir")
+        val serverName = File(cwd).name
+
+        @JvmStatic
+        fun log(message: String, stacktrace: String) = useDb {
+            ExceptionTable.insert {
+                it[ExceptionTable.server] = serverName
+                it[ExceptionTable.message] = generateMessage(message)
+                it[ExceptionTable.stackTrace] = stacktrace
+            }
+
+            Unit
+        }
+
+        @JvmStatic
+        fun logGetId(message: String, stacktrace: String) = useDb {
+            ExceptionTable.insertAndGetId {
+                it[ExceptionTable.server] = serverName
+                it[ExceptionTable.message] = generateMessage(message)
+                it[ExceptionTable.stackTrace] = stacktrace
+            }.value
+        }
+
+        fun generateMessage(message: String): String {
+            val msgBuilder = StringBuilder(message)
+            SQLWrapper.impl.additionalExceptionMetadata(msgBuilder)
+            msgBuilder.append("\nCWD: ").append(cwd)
+            return msgBuilder.toString()
+        }
+    }
+}
\ No newline at end of file
diff --git a/CommonCore/SQL/src/de/steamwar/sql/SchemElo.java b/CommonCore/SQL/src/de/steamwar/sql/SchemElo.java
deleted file mode 100644
index 0a8641b0..00000000
--- a/CommonCore/SQL/src/de/steamwar/sql/SchemElo.java
+++ /dev/null
@@ -1,56 +0,0 @@
-/*
- *   This file is a part of the SteamWar software.
- *
- *   Copyright (C) 2025 SteamWar.de-Serverteam
- *
- *   This program is free software: you can redistribute it and/or modify
- *   it under the terms of the GNU Affero General Public License as published by
- *   the Free Software Foundation, either version 3 of the License, or
- *   (at your option) any later version.
- *
- *   This program is distributed in the hope that it will be useful,
- *   but WITHOUT ANY WARRANTY; without even the implied warranty of
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- *   GNU Affero General Public License for more details.
- *
- *   You should have received a copy of the GNU Affero General Public License
- *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-
-package de.steamwar.sql;
-
-import de.steamwar.sql.internal.Field;
-import de.steamwar.sql.internal.SelectStatement;
-import de.steamwar.sql.internal.Statement;
-import de.steamwar.sql.internal.Table;
-import lombok.AllArgsConstructor;
-
-@AllArgsConstructor
-public class SchemElo {
-    private static final int ELO_DEFAULT = 1000;
-
-    private static final Table<SchemElo> table = new Table<>(SchemElo.class);
-    private static final SelectStatement<SchemElo> select = table.select(Table.PRIMARY);
-    private static final Statement setElo = table.insertAll();
-
-    public static int getElo(SchematicNode node, int season) {
-        SchemElo elo = select.select(node, season);
-        return elo != null ? elo.elo : 0;
-    }
-
-    public static int getCurrentElo(int schemID) {
-        SchemElo elo = select.select(schemID, Season.getSeason());
-        return elo != null ? elo.elo : ELO_DEFAULT;
-    }
-
-    public static void setElo(int schemID, int elo) {
-        setElo.update(schemID, elo, Season.getSeason());
-    }
-
-    @Field(keys = {Table.PRIMARY})
-    private final int schemId;
-    @Field
-    private final int elo;
-    @Field(keys = {Table.PRIMARY})
-    private final int season;
-}
diff --git a/CommonCore/SQL/src/de/steamwar/sql/SchemElo.kt b/CommonCore/SQL/src/de/steamwar/sql/SchemElo.kt
new file mode 100644
index 00000000..fc07f8f4
--- /dev/null
+++ b/CommonCore/SQL/src/de/steamwar/sql/SchemElo.kt
@@ -0,0 +1,75 @@
+/*
+ *   This file is a part of the SteamWar software.
+ *
+ *   Copyright (C) 2025 SteamWar.de-Serverteam
+ *
+ *   This program is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU Affero General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *   GNU Affero General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Affero General Public License
+ *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.steamwar.sql
+
+import de.steamwar.sql.internal.useDb
+import org.jetbrains.exposed.v1.core.and
+import org.jetbrains.exposed.v1.core.dao.id.CompositeID
+import org.jetbrains.exposed.v1.core.dao.id.CompositeIdTable
+import org.jetbrains.exposed.v1.core.dao.id.EntityID
+import org.jetbrains.exposed.v1.core.dao.id.IdTable
+import org.jetbrains.exposed.v1.core.eq
+import org.jetbrains.exposed.v1.dao.CompositeEntity
+import org.jetbrains.exposed.v1.dao.CompositeEntityClass
+import org.jetbrains.exposed.v1.jdbc.insertIgnore
+
+object SchemEloTable: CompositeIdTable("SchemElo") {
+    val schemId = reference("SchemId", SchematicNodeTable)
+    val season = integer("Season").entityId()
+    val elo = integer("Elo")
+
+    override val primaryKey = PrimaryKey(schemId, season)
+
+    init {
+        addIdColumn(schemId)
+    }
+}
+
+class SchemElo(id: EntityID<CompositeID>): CompositeEntity(id) {
+    companion object: CompositeEntityClass<SchemElo>(SchemEloTable) {
+        @JvmStatic
+        fun getElo(node: SchematicNode, season: Int, defaultElo: Int = 0) = useDb {
+            find { (SchemEloTable.schemId eq node.id) and (SchemEloTable.season eq season) }.firstOrNull()?.elo ?: defaultElo
+        }
+
+        @JvmStatic
+        fun getCurrentElo(schemId: Int) = getElo(SchematicNode.byId(schemId)!!, Season.getSeason())
+
+        @JvmStatic
+        fun setElo(node: Int, elo: Int) = useDb {
+            findByIdAndUpdate(CompositeID {
+                it[SchemEloTable.schemId] = node
+                it[SchemEloTable.season] = Season.getSeason()
+            }) {
+                it.elo = elo
+            } ?: SchemEloTable.insertIgnore {
+                it[SchemEloTable.schemId] = node
+                it[SchemEloTable.season] = Season.getSeason()
+                it[SchemEloTable.elo] = elo
+            }
+
+            return@useDb
+        }
+    }
+
+    var node by SchemEloTable.schemId
+    var season by SchemEloTable.season
+    var elo by SchemEloTable.elo
+}
\ No newline at end of file
diff --git a/CommonCore/SQL/src/de/steamwar/sql/Script.java b/CommonCore/SQL/src/de/steamwar/sql/Script.java
deleted file mode 100644
index 1a5ccd25..00000000
--- a/CommonCore/SQL/src/de/steamwar/sql/Script.java
+++ /dev/null
@@ -1,84 +0,0 @@
-/*
- *   This file is a part of the SteamWar software.
- *
- *   Copyright (C) 2025 SteamWar.de-Serverteam
- *
- *   This program is free software: you can redistribute it and/or modify
- *   it under the terms of the GNU Affero General Public License as published by
- *   the Free Software Foundation, either version 3 of the License, or
- *   (at your option) any later version.
- *
- *   This program is distributed in the hope that it will be useful,
- *   but WITHOUT ANY WARRANTY; without even the implied warranty of
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- *   GNU Affero General Public License for more details.
- *
- *   You should have received a copy of the GNU Affero General Public License
- *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-
-package de.steamwar.sql;
-
-import de.steamwar.sql.internal.Field;
-import de.steamwar.sql.internal.SelectStatement;
-import de.steamwar.sql.internal.Statement;
-import de.steamwar.sql.internal.Table;
-import lombok.AllArgsConstructor;
-import lombok.Getter;
-
-import java.util.List;
-
-@AllArgsConstructor
-@Getter
-public class Script {
-
-    private static final Table<Script> table = new Table<>(Script.class);
-
-    private static final SelectStatement<Script> byId = table.select(Table.PRIMARY);
-    private static final SelectStatement<Script> byUserName = table.select("nameUser");
-    private static final SelectStatement<Script> byUser = table.selectFields("userId");
-
-    private static final Statement insert = table.insertFields(true, "userId", "name", "code");
-    private static final Statement updateName = table.update(Table.PRIMARY, "name");
-    private static final Statement updateCode = table.update(Table.PRIMARY, "code");
-    private static final Statement delete = table.delete(Table.PRIMARY);
-
-    public static Script get(int id) {
-        return byId.select(id);
-    }
-
-    public static Script get(SteamwarUser user, String name) {
-        return byUserName.select(user, name);
-    }
-
-    public static Script create(SteamwarUser user, String name, String code) {
-        return new Script(insert.insertGetKey(user, name, code), user.getId(), name, code);
-    }
-
-    public static List<Script> list(SteamwarUser user) {
-        return byUser.listSelect(user);
-    }
-
-    @Field(keys = Table.PRIMARY, autoincrement = true)
-    private final int id;
-    @Field(keys = "nameUser")
-    private final int userId;
-    @Field(keys = "nameUser")
-    private String name;
-    @Field
-    private String code;
-
-    public void setName(String name) {
-        this.name = name;
-        updateName.update(name, id);
-    }
-
-    public void setCode(String code) {
-        this.code = code;
-        updateCode.update(code, id);
-    }
-
-    public void delete() {
-        delete.update(id);
-    }
-}
diff --git a/CommonCore/SQL/src/de/steamwar/sql/Script.kt b/CommonCore/SQL/src/de/steamwar/sql/Script.kt
new file mode 100644
index 00000000..9344db62
--- /dev/null
+++ b/CommonCore/SQL/src/de/steamwar/sql/Script.kt
@@ -0,0 +1,75 @@
+/*
+ *   This file is a part of the SteamWar software.
+ *
+ *   Copyright (C) 2025 SteamWar.de-Serverteam
+ *
+ *   This program is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU Affero General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *   GNU Affero General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Affero General Public License
+ *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.steamwar.sql
+
+import de.steamwar.sql.internal.useDb
+import org.jetbrains.exposed.v1.core.and
+import org.jetbrains.exposed.v1.core.dao.id.EntityID
+import org.jetbrains.exposed.v1.core.dao.id.IntIdTable
+import org.jetbrains.exposed.v1.core.eq
+import org.jetbrains.exposed.v1.dao.IntEntity
+import org.jetbrains.exposed.v1.dao.IntEntityClass
+
+object ScriptTable: IntIdTable("Script") {
+    val userId = reference("UserId", SteamwarUserTable)
+    val name = varchar("Name", 64)
+    val code = text("Code")
+}
+
+class Script(id: EntityID<Int>) : IntEntity(id) {
+    companion object : IntEntityClass<Script>(ScriptTable) {
+        @JvmStatic
+        fun byId(id: Int) = useDb { findById(id) }
+
+        @JvmStatic
+        fun get(user: SteamwarUser, name: String) = useDb {
+            find { ScriptTable.userId eq user.id and (ScriptTable.name eq name) }.firstOrNull()
+        }
+
+        @JvmStatic
+        fun create(user: SteamwarUser, name: String, code: String) = useDb {
+            new {
+                this.userId = user.id.value
+                this.scriptName = name
+                this.scriptCode = code
+            }
+        }
+
+        @JvmStatic
+        fun list(user: SteamwarUser) = useDb {
+            find { ScriptTable.userId eq user.id }.toList()
+        }
+    }
+
+    fun getId() = id.value
+    var userId by ScriptTable.userId.transform({ EntityID(it, SteamwarUserTable) }, { it.value })
+    private var scriptName by ScriptTable.name
+    private var scriptCode by ScriptTable.code
+
+    var name: String
+        get() = scriptName
+        set(value) = useDb { scriptName = value }
+
+    var code: String
+        get() = scriptCode
+        set(value) = useDb { scriptCode = value }
+
+    override fun delete() = useDb { super.delete() }
+}
\ No newline at end of file
diff --git a/CommonCore/SQL/src/de/steamwar/sql/Session.java b/CommonCore/SQL/src/de/steamwar/sql/Session.java
deleted file mode 100644
index 21e2f8f7..00000000
--- a/CommonCore/SQL/src/de/steamwar/sql/Session.java
+++ /dev/null
@@ -1,45 +0,0 @@
-/*
- *   This file is a part of the SteamWar software.
- *
- *   Copyright (C) 2025 SteamWar.de-Serverteam
- *
- *   This program is free software: you can redistribute it and/or modify
- *   it under the terms of the GNU Affero General Public License as published by
- *   the Free Software Foundation, either version 3 of the License, or
- *   (at your option) any later version.
- *
- *   This program is distributed in the hope that it will be useful,
- *   but WITHOUT ANY WARRANTY; without even the implied warranty of
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- *   GNU Affero General Public License for more details.
- *
- *   You should have received a copy of the GNU Affero General Public License
- *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-
-package de.steamwar.sql;
-
-import de.steamwar.sql.internal.Field;
-import de.steamwar.sql.internal.Statement;
-import de.steamwar.sql.internal.Table;
-import lombok.AllArgsConstructor;
-
-import java.sql.Timestamp;
-
-@AllArgsConstructor
-public class Session {
-
-    private static final Table<Session> table = new Table<>(Session.class);
-    private static final Statement insert = table.insert(Table.PRIMARY);
-
-    public static void insertSession(int userID, Timestamp startTime){
-        insert.update(userID, startTime);
-    }
-
-    @Field(keys = {Table.PRIMARY})
-    private int userId;
-    @Field(keys = {Table.PRIMARY})
-    private Timestamp startTime;
-    @Field(def = "CURRENT_TIMESTAMP")
-    private Timestamp endTime;
-}
diff --git a/CommonCore/SQL/src/de/steamwar/sql/Session.kt b/CommonCore/SQL/src/de/steamwar/sql/Session.kt
new file mode 100644
index 00000000..1e50bd08
--- /dev/null
+++ b/CommonCore/SQL/src/de/steamwar/sql/Session.kt
@@ -0,0 +1,46 @@
+/*
+ *   This file is a part of the SteamWar software.
+ *
+ *   Copyright (C) 2025 SteamWar.de-Serverteam
+ *
+ *   This program is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU Affero General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *   GNU Affero General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Affero General Public License
+ *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.steamwar.sql
+
+import de.steamwar.sql.internal.useDb
+import org.jetbrains.exposed.v1.core.Table
+import org.jetbrains.exposed.v1.core.dao.id.EntityID
+import org.jetbrains.exposed.v1.javatime.timestamp
+import org.jetbrains.exposed.v1.jdbc.insert
+import java.sql.Timestamp
+import java.time.Instant
+
+object SessionTable: Table("Session") {
+    val userId = reference("UserId", SteamwarUserTable)
+    val startTime = timestamp("StartTime")
+    val endTime = timestamp("EndTime").default(Instant.now())
+}
+
+class Session {
+    companion object {
+        @JvmStatic
+        fun insertSession(userId: Int, startTime: Timestamp) = useDb {
+            SessionTable.insert {
+                it[SessionTable.userId] = EntityID(userId, SteamwarUserTable)
+                it[SessionTable.startTime] = startTime.toInstant()
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/CommonCore/SQL/src/de/steamwar/sql/SteamwarUser.kt b/CommonCore/SQL/src/de/steamwar/sql/SteamwarUser.kt
index a4dc42ba..33135d9f 100644
--- a/CommonCore/SQL/src/de/steamwar/sql/SteamwarUser.kt
+++ b/CommonCore/SQL/src/de/steamwar/sql/SteamwarUser.kt
@@ -39,7 +39,7 @@ import javax.crypto.spec.PBEKeySpec
 object SteamwarUserTable : IntIdTable("UserData", "id") {
     val uuid = varchar("UUID", 36)
     val username = varchar("UserName", 32)
-    val team = integer("Team")
+    val team = reference("Team", TeamTable)
     val leader = bool("Leader")
     val locale = varchar("Locale", 16).nullable()
     val manualLocale = bool("ManualLocale")
@@ -155,9 +155,9 @@ class SteamwarUser(id: EntityID<Int>): IntEntity(id) {
     var userName by SteamwarUserTable.username
     private var teamInternal by SteamwarUserTable.team
     var team: Int
-        get() = teamInternal
+        get() = teamInternal.value
         set(value) = useDb {
-            teamInternal = value
+            teamInternal = EntityID(value, TeamTable)
             leaderInternal = false
         }
 
diff --git a/CommonCore/SQL/src/de/steamwar/sql/TeamTeilnahme.java b/CommonCore/SQL/src/de/steamwar/sql/TeamTeilnahme.java
deleted file mode 100644
index d7c4c9e6..00000000
--- a/CommonCore/SQL/src/de/steamwar/sql/TeamTeilnahme.java
+++ /dev/null
@@ -1,70 +0,0 @@
-/*
- *   This file is a part of the SteamWar software.
- *
- *   Copyright (C) 2025 SteamWar.de-Serverteam
- *
- *   This program is free software: you can redistribute it and/or modify
- *   it under the terms of the GNU Affero General Public License as published by
- *   the Free Software Foundation, either version 3 of the License, or
- *   (at your option) any later version.
- *
- *   This program is distributed in the hope that it will be useful,
- *   but WITHOUT ANY WARRANTY; without even the implied warranty of
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- *   GNU Affero General Public License for more details.
- *
- *   You should have received a copy of the GNU Affero General Public License
- *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-
-package de.steamwar.sql;
-
-import de.steamwar.sql.internal.Field;
-import de.steamwar.sql.internal.SelectStatement;
-import de.steamwar.sql.internal.Statement;
-import de.steamwar.sql.internal.Table;
-import lombok.AllArgsConstructor;
-
-import java.util.Set;
-import java.util.stream.Collectors;
-
-@AllArgsConstructor
-public class TeamTeilnahme {
-
-    private static final Table<TeamTeilnahme> table = new Table<>(TeamTeilnahme.class);
-    private static final SelectStatement<TeamTeilnahme> select = table.select(Table.PRIMARY);
-    private static final SelectStatement<TeamTeilnahme> selectTeams = table.selectFields("EventID");
-    private static final SelectStatement<TeamTeilnahme> selectEvents = table.selectFields("TeamID");
-    private static final Statement insert = table.insert(Table.PRIMARY);
-    private static final Statement delete = table.delete(Table.PRIMARY);
-    private static final Statement deleteFuture = new Statement("DELETE t FROM TeamTeilnahme t INNER JOIN Event e ON t.EventID = e.EventID WHERE t.TeamID = ? AND e.Start > NOW()");
-
-    @Field(keys = {Table.PRIMARY})
-    private final int teamId;
-    @Field(keys = {Table.PRIMARY})
-    private final int eventId;
-
-    public static boolean nimmtTeil(int teamID, int eventID){
-        return select.select(teamID, eventID) != null;
-    }
-
-    public static void teilnehmen(int teamID, int eventID){
-        insert.update(teamID, eventID);
-    }
-
-    public static void notTeilnehmen(int teamID, int eventID){
-        delete.update(teamID, eventID);
-    }
-
-    public static void deleteFuture(int teamID) {
-        deleteFuture.update(teamID);
-    }
-
-    public static Set<Team> getTeams(int eventID){
-        return selectTeams.listSelect(eventID).stream().map(tt -> Team.byId(tt.teamId)).collect(Collectors.toSet()); // suboptimal performance (O(n) database queries)
-    }
-
-    public static Set<Event> getEvents(int teamID){
-        return selectEvents.listSelect(teamID).stream().map(tt -> Event.byId(tt.eventId)).collect(Collectors.toSet()); // suboptimal performance (O(n) database queries)
-    }
-}
diff --git a/CommonCore/SQL/src/de/steamwar/sql/TeamTeilnahme.kt b/CommonCore/SQL/src/de/steamwar/sql/TeamTeilnahme.kt
new file mode 100644
index 00000000..8a3ef867
--- /dev/null
+++ b/CommonCore/SQL/src/de/steamwar/sql/TeamTeilnahme.kt
@@ -0,0 +1,87 @@
+/*
+ *   This file is a part of the SteamWar software.
+ *
+ *   Copyright (C) 2025 SteamWar.de-Serverteam
+ *
+ *   This program is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU Affero General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *   GNU Affero General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Affero General Public License
+ *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.steamwar.sql
+
+import de.steamwar.sql.internal.useDb
+import org.jetbrains.exposed.v1.core.IntegerColumnType
+import org.jetbrains.exposed.v1.core.and
+import org.jetbrains.exposed.v1.core.dao.id.CompositeID
+import org.jetbrains.exposed.v1.core.dao.id.CompositeIdTable
+import org.jetbrains.exposed.v1.core.dao.id.EntityID
+import org.jetbrains.exposed.v1.core.eq
+import org.jetbrains.exposed.v1.dao.CompositeEntity
+import org.jetbrains.exposed.v1.dao.CompositeEntityClass
+import org.jetbrains.exposed.v1.jdbc.deleteWhere
+import org.jetbrains.exposed.v1.jdbc.insertIgnore
+
+object TeamTeilnahmeTable : CompositeIdTable("TeamTeilnahme") {
+    val teamId = reference("teamId", TeamTable)
+    val eventId = reference("eventId", EventTable)
+
+    override val primaryKey = PrimaryKey(teamId, eventId)
+
+    init {
+        addIdColumn(teamId)
+        addIdColumn(eventId)
+    }
+}
+
+class TeamTeilnahme(id: EntityID<CompositeID>) : CompositeEntity(id) {
+    companion object : CompositeEntityClass<TeamTeilnahme>(TeamTeilnahmeTable) {
+        @JvmStatic
+        fun nimmtTeil(teamId: Int, eventId: Int) = useDb {
+            find { (TeamTeilnahmeTable.teamId eq teamId) and (TeamTeilnahmeTable.eventId eq eventId) }.firstOrNull() != null
+        }
+
+        @JvmStatic
+        fun teilnehmen(teamId: Int, eventId: Int) = useDb {
+            TeamTeilnahmeTable.insertIgnore {
+                it[TeamTeilnahmeTable.teamId] = teamId
+                it[TeamTeilnahmeTable.eventId] = eventId
+            }
+        }
+
+        @JvmStatic
+        fun notTeilnehmen(teamId: Int, eventId: Int) = useDb {
+            TeamTeilnahmeTable.deleteWhere { (TeamTeilnahmeTable.teamId eq teamId) and (TeamTeilnahmeTable.eventId eq eventId) }
+        }
+
+        @JvmStatic
+        fun deleteFuture(teamId: Int) = useDb {
+            exec(
+                "DELETE t FROM TeamTeilnahme t INNER JOIN Event e ON t.EventID = e.EventID WHERE t.TeamID = ? AND e.Start > NOW()",
+                args = listOf(IntegerColumnType() to teamId)
+            )
+        }
+
+        @JvmStatic
+        fun getTeams(eventId: Int) = useDb {
+            find { TeamTeilnahmeTable.eventId eq eventId }.map { it.teamId }
+        }
+
+        @JvmStatic
+        fun getEvents(teamId: Int) = useDb {
+            find { TeamTeilnahmeTable.teamId eq teamId }.map { it.eventId }
+        }
+    }
+
+    val teamId by TeamTeilnahmeTable.teamId
+    val eventId by TeamTeilnahmeTable.eventId
+}
\ No newline at end of file