Information schema #25

OllieJones · 2023-03-22T11:45:50Z

Escaping LIKE literal % and _.
More information_schema and metadata compatiblity.
Unique constraint violations, and other errors when running queries, now detected and reported.
SUBSTRING and CHAR_LENGTH now handled by rewriting the query to SUBSTR and LENGTH.

…ion.

Testing CHAR_LENGTH and SUBSTRING support. Testing LIKE '\_%' (escaped LIKE) support.

Added CHAR_LENGTH and SUBSTRING support as rewrites to LENGTH and SUBSTR. Added LIKE '\_%' (escaped LIKE) support. Corrected GREATEST and LEAST functions, added unit tests.

wp-includes/sqlite/class-wp-sqlite-pdo-user-defined-functions.php

tests/WP_SQLite_Metadata_Tests.php

tests/WP_SQLite_Query_Tests.php

tests/bootstrap.php

wp-includes/sqlite/class-wp-sqlite-translator.php

adamziel · 2023-03-23T09:31:29Z

wp-includes/sqlite/class-wp-sqlite-translator.php

+ if ( str_contains( $unescaped_value, '\_') || str_contains( $unescaped_value, '\%') ) {
+ $this->like_escape_count ++;
+ return str_replace(
+ array ( '\_', '\%' ),


Would _ be a wildcard in a string like \\_? If so, this may require a sub-parser just for the wildcards and backslashes. Lexer already does some of this work, though, to parse the string literals that may look like UPDATE x SET y='\\\'\\\\\\' – I wonder if that code is somehow reusable here.

Yeah, a double backslash turns _ into a wildcard again:

sqlite> select 1 WHERE '\\ot' LIKE '\\_%' ESCAPE '\'; 1

@OllieJones This was marked as resolved but the problem is still there.

adamziel · 2023-03-23T09:37:07Z

Great work on this one @OllieJones! I left some notes but this is the right direction. Do core unit tests still pass?

OllieJones · 2023-03-24T10:28:25Z

By "core" unit tests I guess you mean the ones with this plugin. They do indeed pass.

I've added features and unit tests based on stuff I found in some data-maint plugins.

Thanks for your review; I'll incorporate your changes when I get a chance. LIKE '\_' and LIKE '\%' in my code are a nasty kludge.

adamziel · 2023-03-24T15:11:46Z

By "core" unit tests I guess you mean the ones with this plugin. They do indeed pass.

Oh I meant WordPress core with this plugin installed. I've got almost all of them to pass in #9 and it would be great to avoid regressions:

Tests: 14853, Assertions: 47545, Errors: 15, Failures: 37, Warnings: 34, Skipped: 60, Risky: 2.

The remaining failures can be mostly ignored as they're tests calling private wpdb mysql-related functions.

aristath · 2023-03-27T08:13:22Z

I think we can merge this one as-is and continue iterating in follow-up PR.
What do you think @adamziel @OllieJones ?

adamziel · 2023-03-27T10:12:30Z

@aristath I'd still love to understand how it impacts WordPress core unit tests. What would it take to automate that with a CI check?

Also, I feels strongly about not counting like_expression_nesting separately – it would make the PR simpler = less code to maintain.

OllieJones · 2023-03-27T20:47:37Z

Fixes from your reviews now pushed. It's ready to merge, I think.

Backports changes from WordPress/sqlite-database-integration#25

aristath · 2023-03-28T07:47:47Z

Merged the PR, then fixed some CS issues in 65c50f4 and backported the changes to WordPress/wordpress-develop#3220 as well 👍

Backports changes from WordPress/sqlite-database-integration#25

OllieJones added 11 commits March 4, 2023 18:09

#20 WIP Get Advanced Database Cleaner to work.

cf402f3

#22 Add SUBSTRING( str, pos [,len] ) user-defined function.

6d57b62

#20 #21 Metadata, DDL, report errors better, detect constraint violat…

a9736f4

…ion.

#20 Handle status returns from OPTIMIZE / REPAIR / ANALYZE correctly.

48f234f

#22 #19 Alias functions, transient support, unit tests.

879613a

Testing CHAR_LENGTH and SUBSTRING support. Testing LIKE '\_%' (escaped LIKE) support.

#22 #19 Alias functions, transient support, unit tests.

5a77cb5

Added CHAR_LENGTH and SUBSTRING support as rewrites to LENGTH and SUBSTR. Added LIKE '\_%' (escaped LIKE) support. Corrected GREATEST and LEAST functions, added unit tests.

Back-merge from main

54bbdcf

#20 COUNT(*) from information_schema.

18e599d

set SQLite timeout

60c8bf4

Merge branch 'main' into information-schema

0c8982b

#19 handle LIKE escaping edge cases successfully.

c3d46ec

aristath requested a review from adamziel March 22, 2023 11:52

#19 resolve a couple of merge conflicts

ac250d2

OllieJones requested a review from aristath March 22, 2023 11:55

OllieJones added 2 commits March 22, 2023 07:57

#19 resolve one last merge conflict

f983b56

#26 Correct result set columns from SHOW COLUMNS FROM table.

41e4b42

aristath reviewed Mar 23, 2023

View reviewed changes

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