diff --git a/caosdb-webui b/caosdb-webui
index 7df3c8cdf945e5b98df8b04a084fabbdaf058946..2a6d74d7cb6bed89b2e7a0e5801ff4c040a3ebf8 160000
--- a/caosdb-webui
+++ b/caosdb-webui
@@ -1 +1 @@
-Subproject commit 7df3c8cdf945e5b98df8b04a084fabbdaf058946
+Subproject commit 2a6d74d7cb6bed89b2e7a0e5801ff4c040a3ebf8
diff --git a/src/main/java/caosdb/server/CaosDBServer.java b/src/main/java/caosdb/server/CaosDBServer.java
index 8c67d51405f23f4f8b6f64a3c26b9413a6c5d80b..d52b6e15896ed4724b5d23af4ab1004ad994ca2d 100644
--- a/src/main/java/caosdb/server/CaosDBServer.java
+++ b/src/main/java/caosdb/server/CaosDBServer.java
@@ -48,6 +48,7 @@ import caosdb.server.resource.PermissionRulesResource;
 import caosdb.server.resource.RolesResource;
 import caosdb.server.resource.ScriptingResource;
 import caosdb.server.resource.ServerLogsResource;
+import caosdb.server.resource.ServerPropertiesResource;
 import caosdb.server.resource.TestCaseFileSystemResource;
 import caosdb.server.resource.TestCaseResource;
 import caosdb.server.resource.ThumbnailsResource;
@@ -111,10 +112,7 @@ public class CaosDBServer extends Application {
   private static boolean INSECURE = false;
 
   public static String getServerProperty(final String key) {
-    if (SERVER_PROPERTIES == null) {
-      SERVER_PROPERTIES = ServerProperties.initServerProperties();
-    }
-    return SERVER_PROPERTIES.getProperty(key);
+    return getServerProperties().getProperty(key);
   }
 
   /**
@@ -581,6 +579,7 @@ public class CaosDBServer extends Application {
         .setMatchingMode(Template.MODE_STARTS_WITH);
     protectedRouter.attach("/login?username={username}", AuthenticationResource.class);
     protectedRouter.attach("/logout", LogoutResource.class);
+    protectedRouter.attach("/_server_properties", ServerPropertiesResource.class);
     protectedRouter.attachDefault(DefaultResource.class);
 
     /*
@@ -711,6 +710,13 @@ public class CaosDBServer extends Application {
     }
     SERVER_PROPERTIES.setProperty(key, value);
   }
+
+  public static Properties getServerProperties() {
+    if (SERVER_PROPERTIES == null) {
+      SERVER_PROPERTIES = ServerProperties.initServerProperties();
+    }
+    return SERVER_PROPERTIES;
+  }
 }
 
 class CaosDBComponent extends Component {
diff --git a/src/main/java/caosdb/server/ServerPropertiesSerializer.java b/src/main/java/caosdb/server/ServerPropertiesSerializer.java
new file mode 100644
index 0000000000000000000000000000000000000000..10189f99e2ff30a2d9306ad9dc007810607747dd
--- /dev/null
+++ b/src/main/java/caosdb/server/ServerPropertiesSerializer.java
@@ -0,0 +1,36 @@
+package caosdb.server;
+
+import caosdb.server.utils.Serializer;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Properties;
+import org.jdom2.Element;
+
+public class ServerPropertiesSerializer implements Serializer<Properties, Element> {
+
+  private boolean sort;
+
+  public ServerPropertiesSerializer(boolean sort) {
+    this.sort = sort;
+  }
+
+  public ServerPropertiesSerializer() {
+    this(true);
+  }
+
+  @Override
+  public Element serialize(Properties object) {
+    Element root = new Element("Properties");
+    List<String> names = new ArrayList<>(object.stringPropertyNames());
+    if (sort) {
+      Collections.sort(names);
+    }
+    for (String prop : names) {
+      Element propElem = new Element(prop);
+      propElem.addContent(object.getProperty(prop));
+      root.addContent(propElem);
+    }
+    return root;
+  }
+}
diff --git a/src/main/java/caosdb/server/accessControl/ACMPermissions.java b/src/main/java/caosdb/server/accessControl/ACMPermissions.java
index 40b063f16932c457fe176006c5b7f438a7a2252e..29988106b842fbd2b825899093e102a7448e8951 100644
--- a/src/main/java/caosdb/server/accessControl/ACMPermissions.java
+++ b/src/main/java/caosdb/server/accessControl/ACMPermissions.java
@@ -24,6 +24,7 @@ package caosdb.server.accessControl;
 
 public class ACMPermissions {
 
+  public static final String PERMISSION_ACCESS_SERVER_PROPERTIES = "ACCESS_SERVER_PROPERTIES";
   public static final String PERMISSION_RETRIEVE_SERVERLOGS = "SERVERLOGS:RETRIEVE";
 
   public static final String PERMISSION_RETRIEVE_USER_ROLES(
diff --git a/src/main/java/caosdb/server/database/BackendTransaction.java b/src/main/java/caosdb/server/database/BackendTransaction.java
index a551d5b184ef9c35045697f6f36196665cf648c0..1d5d5c2e68274e664c392a24a901aa4bcd65623b 100644
--- a/src/main/java/caosdb/server/database/BackendTransaction.java
+++ b/src/main/java/caosdb/server/database/BackendTransaction.java
@@ -34,6 +34,7 @@ import caosdb.server.database.backend.implementation.MySQL.MySQLGetFileRecordByP
 import caosdb.server.database.backend.implementation.MySQL.MySQLGetIDByName;
 import caosdb.server.database.backend.implementation.MySQL.MySQLGetInfo;
 import caosdb.server.database.backend.implementation.MySQL.MySQLGetUpdateableChecksums;
+import caosdb.server.database.backend.implementation.MySQL.MySQLInsertEntityDatatype;
 import caosdb.server.database.backend.implementation.MySQL.MySQLInsertEntityProperties;
 import caosdb.server.database.backend.implementation.MySQL.MySQLInsertLinCon;
 import caosdb.server.database.backend.implementation.MySQL.MySQLInsertLogRecord;
@@ -87,6 +88,7 @@ import caosdb.server.database.backend.interfaces.GetFileRecordByPathImpl;
 import caosdb.server.database.backend.interfaces.GetIDByNameImpl;
 import caosdb.server.database.backend.interfaces.GetInfoImpl;
 import caosdb.server.database.backend.interfaces.GetUpdateableChecksumsImpl;
+import caosdb.server.database.backend.interfaces.InsertEntityDatatypeImpl;
 import caosdb.server.database.backend.interfaces.InsertEntityPropertiesImpl;
 import caosdb.server.database.backend.interfaces.InsertLinConImpl;
 import caosdb.server.database.backend.interfaces.InsertLogRecordImpl;
@@ -131,13 +133,11 @@ public abstract class BackendTransaction implements Undoable {
   BackendTransaction parent = null;
   private static HashMap<
           Class<? extends BackendTransactionImpl>, Class<? extends BackendTransactionImpl>>
-      impl =
-          new HashMap<
-              Class<? extends BackendTransactionImpl>, Class<? extends BackendTransactionImpl>>();
+      impl = new HashMap<>();
 
-  protected abstract void execute() throws TransactionException;
+  protected abstract void execute();
 
-  final void executeTransaction() throws TransactionException {
+  final void executeTransaction() {
     final long t1 = System.currentTimeMillis();
     execute();
     final long t2 = System.currentTimeMillis();
@@ -194,10 +194,11 @@ public abstract class BackendTransaction implements Undoable {
       setImpl(SetQueryTemplateDefinitionImpl.class, MySQLSetQueryTemplateDefinition.class);
       setImpl(
           RetrieveQueryTemplateDefinitionImpl.class, MySQLRetrieveQueryTemplateDefinition.class);
+      setImpl(InsertEntityDatatypeImpl.class, MySQLInsertEntityDatatype.class);
     }
   }
 
-  protected <K extends BackendTransaction> K execute(final K t) throws TransactionException {
+  protected <K extends BackendTransaction> K execute(final K t) {
     assert t != this;
     this.undoHandler.append(t);
     t.setAccess(this.access);
@@ -219,8 +220,7 @@ public abstract class BackendTransaction implements Undoable {
   }
 
   @SuppressWarnings("unchecked")
-  protected <T extends BackendTransactionImpl> T getImplementation(final Class<T> clz)
-      throws TransactionException {
+  protected <T extends BackendTransactionImpl> T getImplementation(final Class<T> clz) {
     init();
     try {
       final T ret = (T) impl.get(clz).getConstructor(Access.class).newInstance(this.access);
diff --git a/src/main/java/caosdb/server/database/backend/implementation/MySQL/MySQLInsertEntityDatatype.java b/src/main/java/caosdb/server/database/backend/implementation/MySQL/MySQLInsertEntityDatatype.java
new file mode 100644
index 0000000000000000000000000000000000000000..a2682e80b1997b53496e3ac2f8e6147726fb77c9
--- /dev/null
+++ b/src/main/java/caosdb/server/database/backend/implementation/MySQL/MySQLInsertEntityDatatype.java
@@ -0,0 +1,52 @@
+package caosdb.server.database.backend.implementation.MySQL;
+
+import caosdb.server.database.access.Access;
+import caosdb.server.database.backend.interfaces.InsertEntityDatatypeImpl;
+import caosdb.server.database.exceptions.IntegrityException;
+import caosdb.server.database.exceptions.TransactionException;
+import caosdb.server.database.proto.SparseEntity;
+import java.sql.PreparedStatement;
+import java.sql.SQLIntegrityConstraintViolationException;
+
+public class MySQLInsertEntityDatatype extends MySQLTransaction
+    implements InsertEntityDatatypeImpl {
+
+  public MySQLInsertEntityDatatype(Access access) {
+    super(access);
+  }
+
+  public static final String STMT_INSERT_ENTITY_DATATYPE =
+      "INSERT INTO data_type (domain_id, entity_id, property_id, datatype) SELECT 0, 0, ?, ( SELECT id from entities where name = ? LIMIT 1);";
+  public static final String STMT_INSERT_ENTITY_COLLECTION =
+      "INSERT INTO collection_type (domain_id, entity_id, property_id, collection) SELECT 0, 0, ?, ?;";
+
+  @Override
+  public void execute(final SparseEntity entity) {
+    try {
+      final PreparedStatement insertEntityDatatypeStmt =
+          prepareStatement(STMT_INSERT_ENTITY_DATATYPE);
+
+      insertEntityDatatypeStmt.setInt(1, entity.id);
+      insertEntityDatatypeStmt.setString(2, entity.datatype);
+
+      insertEntityDatatypeStmt.execute();
+
+      if (entity.collection != null) {
+        final PreparedStatement insertEntityCollectionStmt =
+            prepareStatement(STMT_INSERT_ENTITY_COLLECTION);
+
+        insertEntityCollectionStmt.setInt(1, entity.id);
+        insertEntityCollectionStmt.setString(2, entity.collection);
+
+        insertEntityCollectionStmt.execute();
+      }
+
+    } catch (final SQLIntegrityConstraintViolationException exc) {
+      throw new IntegrityException(exc);
+    } catch (final TransactionException exc) {
+      throw exc;
+    } catch (final Exception exc) {
+      throw new TransactionException(exc);
+    }
+  }
+}
diff --git a/src/main/java/caosdb/server/database/backend/implementation/MySQL/MySQLInsertSparseEntity.java b/src/main/java/caosdb/server/database/backend/implementation/MySQL/MySQLInsertSparseEntity.java
index dbe3893945ae09cadfda0657f9d22d02bd6a9371..4ad9f5b6a3cc3e51c05bc83bbc9332807b79484d 100644
--- a/src/main/java/caosdb/server/database/backend/implementation/MySQL/MySQLInsertSparseEntity.java
+++ b/src/main/java/caosdb/server/database/backend/implementation/MySQL/MySQLInsertSparseEntity.java
@@ -38,12 +38,12 @@ public class MySQLInsertSparseEntity extends MySQLTransaction implements InsertS
     super(access);
   }
 
-  public static final String STMT_INSERT_SPARSE_ENTITY = "call insertEntity(?,?,?,?,?,?)";
+  public static final String STMT_INSERT_SPARSE_ENTITY = "call insertEntity(?,?,?,?)";
   public static final String STMT_INSERT_FILE_PROPERTIES =
       "INSERT INTO files (file_id, hash, size, path) VALUES (?, unhex(?), ?, ?);";
 
   @Override
-  public void execute(final SparseEntity entity) throws TransactionException {
+  public void execute(final SparseEntity entity) {
     try {
       final PreparedStatement insertEntityStmt = prepareStatement(STMT_INSERT_SPARSE_ENTITY);
       final PreparedStatement insertFilePropsStmt = prepareStatement(STMT_INSERT_FILE_PROPERTIES);
@@ -51,15 +51,14 @@ public class MySQLInsertSparseEntity extends MySQLTransaction implements InsertS
       insertEntityStmt.setString(1, entity.name);
       insertEntityStmt.setString(2, entity.description);
       insertEntityStmt.setString(3, entity.role);
-      insertEntityStmt.setString(4, entity.datatype);
-      insertEntityStmt.setString(5, entity.collection);
-      insertEntityStmt.setString(6, entity.acl);
+      insertEntityStmt.setString(4, entity.acl);
 
-      final ResultSet rs = insertEntityStmt.executeQuery();
-      if (rs.next()) {
-        entity.id = rs.getInt("EntityID");
-      } else {
-        throw new TransactionException("Didn't get new EntityID back.");
+      try (final ResultSet rs = insertEntityStmt.executeQuery()) {
+        if (rs.next()) {
+          entity.id = rs.getInt("EntityID");
+        } else {
+          throw new TransactionException("Didn't get new EntityID back.");
+        }
       }
 
       if (entity.filePath != null) {
diff --git a/src/main/java/caosdb/server/database/backend/interfaces/InsertEntityDatatypeImpl.java b/src/main/java/caosdb/server/database/backend/interfaces/InsertEntityDatatypeImpl.java
new file mode 100644
index 0000000000000000000000000000000000000000..2f6f7c859281344997e1c781e9a56aafa5d03fc4
--- /dev/null
+++ b/src/main/java/caosdb/server/database/backend/interfaces/InsertEntityDatatypeImpl.java
@@ -0,0 +1,8 @@
+package caosdb.server.database.backend.interfaces;
+
+import caosdb.server.database.proto.SparseEntity;
+import caosdb.server.utils.Undoable;
+
+public interface InsertEntityDatatypeImpl extends BackendTransactionImpl, Undoable {
+  public abstract void execute(SparseEntity entity);
+}
diff --git a/src/main/java/caosdb/server/database/backend/interfaces/InsertSparseEntityImpl.java b/src/main/java/caosdb/server/database/backend/interfaces/InsertSparseEntityImpl.java
index 7ba147058b8c4675d58b66a5c11b7dd66311cabf..8ad9a9f7ac0608c4e1e51ba4783a985d0e20d985 100644
--- a/src/main/java/caosdb/server/database/backend/interfaces/InsertSparseEntityImpl.java
+++ b/src/main/java/caosdb/server/database/backend/interfaces/InsertSparseEntityImpl.java
@@ -22,11 +22,10 @@
  */
 package caosdb.server.database.backend.interfaces;
 
-import caosdb.server.database.exceptions.TransactionException;
 import caosdb.server.database.proto.SparseEntity;
 import caosdb.server.utils.Undoable;
 
 public interface InsertSparseEntityImpl extends BackendTransactionImpl, Undoable {
 
-  public abstract void execute(SparseEntity entity) throws TransactionException;
+  public abstract void execute(SparseEntity entity);
 }
diff --git a/src/main/java/caosdb/server/database/backend/transaction/InsertEntity.java b/src/main/java/caosdb/server/database/backend/transaction/InsertEntity.java
index 65611a4193e8bb494666fb91c3a07a59b4aabd99..e258504908b44c8054a56315fa26e8dacae8b023 100644
--- a/src/main/java/caosdb/server/database/backend/transaction/InsertEntity.java
+++ b/src/main/java/caosdb/server/database/backend/transaction/InsertEntity.java
@@ -23,7 +23,6 @@
 package caosdb.server.database.backend.transaction;
 
 import caosdb.server.database.BackendTransaction;
-import caosdb.server.database.exceptions.TransactionException;
 import caosdb.server.entity.EntityInterface;
 import caosdb.server.entity.container.TransactionContainer;
 import caosdb.server.utils.EntityStatus;
@@ -37,12 +36,17 @@ public class InsertEntity extends BackendTransaction {
   }
 
   @Override
-  public void execute() throws TransactionException {
+  public void execute() {
     for (final EntityInterface newEntity : this.container) {
       if (newEntity.getEntityStatus() == EntityStatus.QUALIFIED) {
         execute(new InsertSparseEntity(newEntity));
       }
     }
+    for (final EntityInterface newEntity : this.container) {
+      if (newEntity.getEntityStatus() == EntityStatus.QUALIFIED && newEntity.hasDatatype()) {
+        execute(new InsertEntityDatatype(newEntity));
+      }
+    }
     for (final EntityInterface newEntity : this.container) {
       if (newEntity.getEntityStatus() == EntityStatus.QUALIFIED) {
         if (newEntity.getQueryTemplateDefinition() != null) {
@@ -51,7 +55,6 @@ public class InsertEntity extends BackendTransaction {
         if (newEntity.hasFileProperties()) {
           execute(new InsertFile(newEntity));
         }
-        // execute(new InsertEntityValue(newEntity));
         execute(new InsertEntityProperties(newEntity));
         execute(new InsertParents(newEntity));
 
diff --git a/src/main/java/caosdb/server/database/backend/transaction/InsertEntityDatatype.java b/src/main/java/caosdb/server/database/backend/transaction/InsertEntityDatatype.java
new file mode 100644
index 0000000000000000000000000000000000000000..39c46583cc277eb81128d9fae22d97e296d8bbc1
--- /dev/null
+++ b/src/main/java/caosdb/server/database/backend/transaction/InsertEntityDatatype.java
@@ -0,0 +1,36 @@
+package caosdb.server.database.backend.transaction;
+
+import static caosdb.server.transaction.Transaction.ERROR_INTEGRITY_VIOLATION;
+
+import caosdb.server.database.BackendTransaction;
+import caosdb.server.database.backend.interfaces.InsertEntityDatatypeImpl;
+import caosdb.server.database.exceptions.IntegrityException;
+import caosdb.server.database.proto.SparseEntity;
+import caosdb.server.entity.EntityInterface;
+import caosdb.server.utils.EntityStatus;
+
+public class InsertEntityDatatype extends BackendTransaction {
+
+  private final EntityInterface entity;
+
+  public InsertEntityDatatype(final EntityInterface entity) {
+    this.entity = entity;
+  }
+
+  @Override
+  public void execute() {
+    final InsertEntityDatatypeImpl t = getImplementation(InsertEntityDatatypeImpl.class);
+
+    final SparseEntity e = this.entity.getSparseEntity();
+
+    try {
+      t.execute(e);
+    } catch (final IntegrityException exc) {
+      this.entity.addError(ERROR_INTEGRITY_VIOLATION);
+      this.entity.setEntityStatus(EntityStatus.CORRUPT);
+      throw exc;
+    }
+
+    this.entity.setId(e.id);
+  }
+}
diff --git a/src/main/java/caosdb/server/resource/AbstractCaosDBServerResource.java b/src/main/java/caosdb/server/resource/AbstractCaosDBServerResource.java
index 5a32cf795b661537f3dbc07fe8717aff4d8a0242..e8bc5f4932f4c3972b6e64bd5d234e8c7898794b 100644
--- a/src/main/java/caosdb/server/resource/AbstractCaosDBServerResource.java
+++ b/src/main/java/caosdb/server/resource/AbstractCaosDBServerResource.java
@@ -313,19 +313,29 @@ public abstract class AbstractCaosDBServerResource extends ServerResource {
     return new JdomRepresentation(doc, MediaType.TEXT_XML, "  ", getReference(), getXSLScript());
   }
 
-  protected JdomRepresentation error(final Message m, final Status status) {
+  protected Representation error(final Message m, final Status status) {
     final Document doc = new Document();
     final Element root = generateRootElement();
     root.addContent(m.toElement().setName("Error"));
     doc.setRootElement(root);
+    return error(
+        new JdomRepresentation(doc, MediaType.TEXT_XML, "  ", getReference(), getXSLScript()),
+        status);
+  }
+
+  protected Representation error(Representation entity, Status status) {
     getResponse().setStatus(status);
-    return new JdomRepresentation(doc, MediaType.TEXT_XML, "  ", getReference(), getXSLScript());
+    return entity;
   }
 
-  protected JdomRepresentation error(final Message m) {
+  protected Representation error(final Message m) {
     return error(m, Status.SERVER_ERROR_INTERNAL);
   }
 
+  protected Representation error(final Status status) {
+    return error((Representation) null, status);
+  }
+
   protected JdomRepresentation warning(final Message m) {
     final Document doc = new Document();
     final Element root = generateRootElement();
@@ -334,19 +344,19 @@ public abstract class AbstractCaosDBServerResource extends ServerResource {
     return new JdomRepresentation(doc, MediaType.TEXT_XML, "  ", getReference(), getXSLScript());
   }
 
-  protected JdomRepresentation noWellFormedNess() {
+  protected Representation noWellFormedNess() {
     return error(ServerMessages.REQUEST_BODY_NOT_WELLFORMED);
   }
 
-  protected JdomRepresentation emptyEntity() {
+  protected Representation emptyEntity() {
     return error(ServerMessages.REQUEST_BODY_EMPTY);
   }
 
-  protected JdomRepresentation connectionFailed() {
+  protected Representation connectionFailed() {
     return error(ServerMessages.CANNOT_CONNECT_TO_DATABASE);
   }
 
-  public JdomRepresentation handleThrowable(final Throwable t) {
+  public Representation handleThrowable(final Throwable t) {
     try {
       getRequest().getAttributes().put("THROWN", t);
       throw t;
diff --git a/src/main/java/caosdb/server/resource/ServerPropertiesResource.java b/src/main/java/caosdb/server/resource/ServerPropertiesResource.java
new file mode 100644
index 0000000000000000000000000000000000000000..9b878e3338a9d0b0c74704acb412ac92ceb1f0c4
--- /dev/null
+++ b/src/main/java/caosdb/server/resource/ServerPropertiesResource.java
@@ -0,0 +1,42 @@
+package caosdb.server.resource;
+
+import caosdb.server.CaosDBServer;
+import caosdb.server.ServerPropertiesSerializer;
+import caosdb.server.accessControl.ACMPermissions;
+import org.restlet.data.Form;
+import org.restlet.data.Parameter;
+import org.restlet.data.Status;
+import org.restlet.representation.Representation;
+
+public class ServerPropertiesResource extends AbstractCaosDBServerResource {
+
+  @Override
+  protected void doInit() {
+    super.doInit();
+    setXSLScript("xsl/server_properties.xsl");
+  }
+
+  @Override
+  protected Representation httpGetInChildClass() {
+    if (CaosDBServer.isDebugMode()) {
+      getUser().checkPermission(ACMPermissions.PERMISSION_ACCESS_SERVER_PROPERTIES);
+      return super.ok(
+          new ServerPropertiesSerializer().serialize(CaosDBServer.getServerProperties()));
+    }
+    return error(Status.CLIENT_ERROR_NOT_FOUND);
+  }
+
+  @Override
+  protected Representation httpPostInChildClass(Representation entity) {
+    if (CaosDBServer.isDebugMode()) {
+      getUser().checkPermission(ACMPermissions.PERMISSION_ACCESS_SERVER_PROPERTIES);
+      Form form = new Form(entity);
+      for (Parameter param : form) {
+        CaosDBServer.setProperty(param.getName(), param.getValue());
+      }
+      return super.ok(
+          new ServerPropertiesSerializer().serialize(CaosDBServer.getServerProperties()));
+    }
+    return error(Status.CLIENT_ERROR_NOT_FOUND);
+  }
+}