Fixed that schema changes while the database was open would break any connections to a SQLite database (now we reconnect if that error is throw) [DHH]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3997 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

2 files changed, 16 insertions, 2 deletions

diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index d34aef9477..7949a1736d 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Fixed that schema changes while the database was open would break any connections to a SQLite database (now we reconnect if that error is throw) [DHH]
+
 * Don't classify the has_one class when eager loading, it is already singular. Add tests. (closes #4117) [jonathan@bluewire.net.nz]
 
 * Quit ignoring default :include options in has_many :through calls [Mark James]
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
index bc874ee58b..ab5c9b822f 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
@@ -135,6 +135,13 @@ module ActiveRecord
 
       def execute(sql, name = nil) #:nodoc:
         log(sql, name) { @connection.execute(sql) }
+      rescue ActiveRecord::StatementInvalid => exception
+        if exception.message =~ /database schema has changed/
+          reconnect!
+          retry
+        else
+          raise
+        end
       end
 
       def update(sql, name = nil) #:nodoc:
@@ -341,13 +348,18 @@ module ActiveRecord
       # 
       #   SELECT COUNT(ArtistID) FROM (SELECT DISTINCT ArtistID FROM CDs);
       def execute(sql, name = nil) #:nodoc:
+        super(rewrite_count_distinct_queries(sql), name)
+      end
+      
+      def rewrite_count_distinct_queries(sql)
         if sql =~ /count\(distinct ([^\)]+)\)( AS \w+)? (.*)/i
           distinct_column = $1
           distinct_query  = $3
           column_name     = distinct_column.split('.').last
-          sql             = "SELECT COUNT(#{column_name}) FROM (SELECT DISTINCT #{distinct_column} #{distinct_query})"
+          "SELECT COUNT(#{column_name}) FROM (SELECT DISTINCT #{distinct_column} #{distinct_query})"
+        else
+          sql
         end
-        log(sql, name) { @connection.execute(sql) }
       end
     end