Destroys table's constraints on table's drop

app/models/table.rb

@@ -149,6 +149,11 @@ class Table < Sequel::Model(:user_tables)
     end
   end
 
+  def before_destroy
+    super
+    delete_constraints
+  end
+
   def after_destroy
     super
     Tag.filter(:user_id => user_id, :table_id => id).delete
@@ -460,6 +465,18 @@ class Table < Sequel::Model(:user_tables)
     owner.run_query(query)
   end
 
+  def constraints
+    owner.in_database do |user_database|
+      table_constraints_sql = <<-SQL
+        SELECT constraint_name
+        FROM information_schema.table_constraints
+        WHERE table_name = ? AND constraint_name = ?
+      SQL
+
+      user_database.fetch(table_constraints_sql, name, 'enforce_srid_the_geom').all
+    end
+  end
+
   private
 
   def update_updated_at
@@ -622,6 +639,14 @@ class Table < Sequel::Model(:user_tables)
     end
   end
 
+  def delete_constraints
+    owner.in_database do |user_database|
+      user_database.alter_table(self.name.to_sym) do
+        drop_constraint(:enforce_srid_the_geom)
+      end
+    end
+  end
+
   def set_triggers
     owner.in_database(:as => :superuser) do |user_database|
       user_database.run(<<-TRIGGER

spec/models/table_spec.rb

@@ -310,6 +310,7 @@ describe Table do
     table.destroy
     user.reload
     user.tables_count.should == 0
+    table.constraints.count.should == 0
     Tag.count.should == 0
     Table.count == 0
   end
@@ -886,4 +887,11 @@ describe Table do
     table.lon_column.should == :new_longitude
   end
 
+  it "should return all table's constraints" do
+    user = create_user
+    table = create_table :user_id => user.id
+    puts table.constraints
+    table.constraints.should have_at_least(1).item
+    table.constraints.should include({:constraint_name => 'enforce_srid_the_geom'})
+  end
 end