Change SHOW COLUMNS query to display MySQL types in MySQL Compatibility mode

[tpanetti]

This updates the SHOW COLUMN SQL query to display MySQL types when this query is issued by a client connected via MySQL Compatibility port

Changelog category (leave one):

• New Feature

Changelog entry (a user-readable short description of the changes that goes to CHANGELOG.md):

Add a new setting named use_mysql_types_in_show_columns to alter the SHOW COLUMNS SQL statement to display MySQL equivalent types when a client is connected via the MySQL compatibility port.

Documentation entry for user-facing changes

• Documentation is written (mandatory for new features)

Motivation: This functionality is useful for ClickHouse users as it allows tools that use standard MySQL connectors to read and parse ClickHouse data as if it were MySQL. This is particularly useful for data analytics tools such as QuickSights and Looker Studio.
Parameters: No arguments or parameters are needed, this type conversion is done when a client is connected via the MySQL port. Specifically, the implementation happens when the client is connected to whatever port the configuration has set for MySQL compatibility.
Example use:
SHOW FULL COLUMNS

I've attached an image of Amazon QuickSight parsing a ClickHouse database with example cell_towers data with this code change.

Information about CI checks: https://clickhouse.com/docs/en/development/continuous-integration/

Closes #49168

[CLAassistant]

All committers have signed the CLA.

[robot-ch-test-poll]

This is an automated comment for commit dbdf77c with description of existing statuses. It's updated for the latest CI running
The full report is available here
The overall status of the commit is 🔴 failure

Check name	Description	Status
AST fuzzer	Runs randomly generated queries to catch program errors. The build type is optionally given in parenthesis. If it fails, ask a maintainer for help	🟢 success
CI running	A meta-check that indicates the running CI. Normally, it's in success or pending state. The failed status indicates some problems with the PR	🟢 success
ClickHouse build check	Builds ClickHouse in various configurations for use in further steps. You have to fix the builds that fail. Build logs often has enough information to fix the error, but you might have to reproduce the failure locally. The cmake options can be found in the build log, grepping for cmake. Use these options and follow the general build process	🟢 success
Compatibility check	Checks that clickhouse binary runs on distributions with old libc versions. If it fails, ask a maintainer for help	🟢 success
Docker image for servers	The check to build and optionally push the mentioned image to docker hub	🟢 success
Fast test	Normally this is the first check that is ran for a PR. It builds ClickHouse and runs most of stateless functional tests, omitting some. If it fails, further checks are not started until it is fixed. Look at the report to see which tests fail, then reproduce the failure locally as described here	🟢 success
Flaky tests	Checks if new added or modified tests are flaky by running them repeatedly, in parallel, with more randomization. Functional tests are run 100 times with address sanitizer, and additional randomization of thread scheduling. Integrational tests are run up to 10 times. If at least once a new test has failed, or was too long, this check will be red. We don't allow flaky tests, read the doc	🟢 success
Install packages	Checks that the built packages are installable in a clear environment	🟢 success
Integration tests	The integration tests report. In parenthesis the package type is given, and in square brackets are the optional part/total tests	🔴 failure
Mergeable Check	Checks if all other necessary checks are successful	🟢 success
Performance Comparison	Measure changes in query performance. The performance test report is described in detail here. In square brackets are the optional part/total tests	🟢 success
Push to Dockerhub	The check for building and pushing the CI related docker images to docker hub	🟢 success
SQLancer	Fuzzing tests that detect logical bugs with SQLancer tool	🟢 success
Sqllogic	Run clickhouse on the sqllogic test set against sqlite and checks that all statements are passed	🟢 success
Stateful tests	Runs stateful functional tests for ClickHouse binaries built in various configurations -- release, debug, with sanitizers, etc	🟢 success
Stateless tests	Runs stateless functional tests for ClickHouse binaries built in various configurations -- release, debug, with sanitizers, etc	🔴 failure
Stress test	Runs stateless functional tests concurrently from several clients to detect concurrency-related errors	🟢 success
Style Check	Runs a set of checks to keep the code style clean. If some of tests failed, see the related log from the report	🟢 success
Unit tests	Runs the unit tests for different release types	🟢 success
Upgrade check	Runs stress tests on server version from last release and then tries to upgrade it to the version from the PR. It checks if the new server can successfully startup without any errors, crashes or sanitizer asserts	🟢 success

[tpanetti]

Refactored to a more scalable method of implementation via the IDataType interface. Added @rschu1ze as an additional reviewer after discussions with him about this change. For incompatible types (eg int64, int128) I chose to default to text for compatibility with BI tools, this may warrant further discussion though.

[alexey-milovidov]

Ok. Need to fix the test. Copy-paste the initialization header from similar .sh tests.

[alexey-milovidov]

Let's rename getMySQLName to getSQLCompatibleName, and change the returned value to ALL CAPS (TEXT, etc).

[rschu1ze]

Lgtm (thanks) but the tests still fail in a weird way.

E.g. here: https://s3.amazonaws.com/clickhouse-test-reports/49577/cb8c20722b8976fe0bc402498667b02c2585cc02/stateless_tests_flaky_check__asan_.html

I did not check deeper but there can be a race on database name database_123456789abcde when the test runs in parallel. You could use tag "no-parallel" at the top of the test file to suppress parallel execution.

[Avogar]

Suggested change

	${CLICKHOUSE_LOCAL} --query "DROP TABLE IF EXISTS database_123456789abcde"
	${CLICKHOUSE_LOCAL} --query "DROP DATABASE IF EXISTS database_123456789abcde"

[tpanetti]

Fixed

[rschu1ze]

ClickHouse Integration Tests (asan) [6/6]:

• test_ssl_cert_authentication: Flaky test test_ssl_cert_authentication #49400

ClickHouse Stateless Tests (debug) [2/5]

• 02703_max_local_write_bandwidth 02703_max_local_write_bandwidth is flaky #51221
• 02561_null_as_default_more_formats 02561_null_as_default_more_formats is flaky #49177

[antonio2368]

no-parallel can be removed and ${CLICKHOUSE_DATABASE} can be used to get the unique generated database for this test.

[antonio2368]

@tpanetti good job on the first merged PR!

Can you modify the Changelog category in the description because of the setting it's not Backward Incompatible Change anymore.
Also, you can mention the setting in the changelog description so it's easier for people to find how to use it.

[alexey-milovidov]

Documentation is written (mandatory for new features)

Checked as it is written in the code.