Support read queries with leading characters while preventing writes #35402
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
* The READ_QUERY regex would consider reads to be writes if they started with
spaces or parens. For example, a UNION query might have parens around each
SELECT - (SELECT ...) UNION (SELECT ...).
* It will now correctly treat these queries as reads.
alimi
commented
Feb 25, 2019
| @conn.execute("INSERT INTO ex (data) VALUES ('138853948594')") | ||
|
|
||
| @conn.while_preventing_writes do | ||
| assert_equal 1, @conn.execute(" SELECT data from ex WHERE data = '138853948594'").count |
There was a problem hiding this comment.
I didn't add leading parenthesis to the sqlite3 test because sqlite3 didn't consider it valid syntax.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Summary
#34505 introduced the ability to block writes even if the database allows it. It added a
READ_QUERYregex to help determine if a query was a read or a write. The regex is built usingActiveRecord::ConnectionAdapters::AbstractAdapter.build_read_query_regexpand it doesn't account for reads with leading parenthesis and/or spaces.rails/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
Lines 104 to 106 in 67732ef
This would cause read queries like unions (
(SELECT ...) UNION (SELECT ...)) to be treated as writes.In this PR, I update the regex allow for leading parenthesis and/or spaces.