Rename error that occurs when writing on a read

I originally named this `StatementInvalid` because that's what we do in
GitHub, but `@tenderlove` pointed out that this means apps can't test
for or explitly rescue this error. `StatementInvalid` is pretty broad so
I've renamed this to `ReadOnlyError`.

1 files changed, 1 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb
index 2d5b592639..d93c1f449e 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb
@@ -80,7 +80,7 @@ module ActiveRecord
         # need it specifically, you may want consider the <tt>exec_query</tt> wrapper.
         def execute(sql, name = nil)
           if preventing_writes? && write_query?(sql)
-            raise ActiveRecord::StatementInvalid, "Write query attempted while in readonly mode: #{sql}"
+            raise ActiveRecord::ReadOnlyError, "Write query attempted while in readonly mode: #{sql}"
           end
 
           materialize_transactions