There was a way to prevent a database from being re-opened, by creating a column…

There was a way to prevent a database from being re-opened, by creating a column constraint that references a table with a higher id.

h2/src/main/org/h2/command/ddl/CreateTable.java

@@ -7,12 +7,14 @@
 package org.h2.command.ddl;
 
 import java.util.ArrayList;
+import java.util.HashSet;
 
 import org.h2.api.ErrorCode;
 import org.h2.command.CommandInterface;
 import org.h2.command.dml.Insert;
 import org.h2.command.dml.Query;
 import org.h2.engine.Database;
+import org.h2.engine.DbObject;
 import org.h2.engine.Session;
 import org.h2.expression.Expression;
 import org.h2.message.DbException;
@@ -186,6 +188,28 @@ public class CreateTable extends SchemaCommand {
                     session.setUndoLogEnabled(old);
                 }
             }
+            HashSet<DbObject> set = New.hashSet();
+            set.clear();
+            table.addDependencies(set);
+            for (DbObject obj : set) {
+                if (obj == table) {
+                    continue;
+                }
+                if (obj.getType() == DbObject.TABLE_OR_VIEW) {
+                    if (obj instanceof Table) {
+                        Table t = (Table) obj;
+                        if (t.getId() > table.getId()) {
+                            throw DbException.get(
+                                    ErrorCode.FEATURE_NOT_SUPPORTED_1,
+                                    "Table depends on another table " + 
+                                    "with a higher ID: " + t + 
+                                    ", this is currently not supported, " + 
+                                    "as it would prevent the database from " + 
+                                    "beeing re-opened");
+                        }
+                    }
+                }
+            }
         } catch (DbException e) {
             db.checkPowerOff();
             db.removeSchemaObject(session, table);

h2/src/test/org/h2/test/db/TestCases.java

@@ -41,6 +41,7 @@ public class TestCases extends TestBase {
 
     @Override
     public void test() throws Exception {
+        testReferenceLaterTable();
         testAutoCommitInDatabaseURL();
         testReferenceableIndexUsage();
         testClearSyntaxException();
@@ -107,6 +108,23 @@ public class TestCases extends TestBase {
         deleteDb("cases");
     }
     
+    private void testReferenceLaterTable() throws SQLException {
+        deleteDb("cases");
+        Connection conn = getConnection("cases");
+        Statement stat = conn.createStatement();
+        stat.execute("create table a(id int)");
+        stat.execute("create table b(id int)");
+        stat.execute("drop table a");
+        assertThrows(ErrorCode.FEATURE_NOT_SUPPORTED_1, stat).
+            execute("create table a(id int check id < select max(id) from b)");
+        stat.execute("drop table b");
+        stat.execute("create table b(id int)");
+        stat.execute("create table a(id int check id < select max(id) from b)");
+        conn.close();
+        conn = getConnection("cases");
+        conn.close();
+    }
+
     private void testAutoCommitInDatabaseURL() throws SQLException {
         Connection conn = getConnection("cases;autocommit=false");
         assertFalse(conn.getAutoCommit());