Use DECIMAL instead of INTEGER when casting as mysql doesn't work with just "INTEGER" and other databases don't like "UNSIGNED" which mysql requires

And don't mask exceptions.

Signed-off-by: Jeremy Kemper <jeremy@bitsweat.net>

activerecord/lib/active_record/migration.rb

@@ -407,9 +407,14 @@ module ActiveRecord
       end
 
       def current_version
-        Base.connection.select_value(
-          "SELECT MAX(CAST(version AS integer)) FROM #{schema_migrations_table_name}"
-        ).to_i rescue 0
+        sm_table = schema_migrations_table_name
+        if Base.connection.table_exists?(sm_table)
+          Base.connection.select_value(
+            "SELECT MAX(CAST(version AS DECIMAL)) FROM #{sm_table}"
+          ).to_i
+        else
+          0
+        end
       end
 
       def proper_table_name(name)