Convering enum to varchar

[shlomi-noach]

Related issue: github#642

Description

Looking into -alter converting an enum into varchar. Per github#642 this copies the numeric value of the enum into the varchar column, where we want the textual value.

Initial commit: test suite to confirm error.

[shlomi-noach]

As expected, the test fails (https://github.com/openark/gh-ost/pull/18/checks?check_run_id=2486957737):

2021-05-02T15:40:48.8743290Z Testing: enum-to-varchar......ERROR enum-to-varchar: checksum mismatch
2021-05-02T15:40:48.8745797Z ---
2021-05-02T15:40:48.8991055Z 8,22c8,22
2021-05-02T15:40:48.8991705Z < 8	11	red
2021-05-02T15:40:48.8992338Z < 9	13	green
2021-05-02T15:40:48.8992817Z < 10	17	orange
2021-05-02T15:40:48.8993447Z < 11	11	red
2021-05-02T15:40:48.8993963Z < 12	13	green
2021-05-02T15:40:48.8994656Z < 13	17	orange
2021-05-02T15:40:48.8995048Z < 14	11	red
2021-05-02T15:40:48.8995471Z < 15	13	green
2021-05-02T15:40:48.8995827Z < 16	17	orange
2021-05-02T15:40:48.8996188Z < 17	11	red
2021-05-02T15:40:48.8996675Z < 18	13	green
2021-05-02T15:40:48.8997031Z < 19	17	orange
2021-05-02T15:40:48.8997360Z < 20	11	red
2021-05-02T15:40:48.8997701Z < 21	13	green
2021-05-02T15:40:48.8998051Z < 22	17	orange
2021-05-02T15:40:48.8998784Z ---
2021-05-02T15:40:48.8999111Z > 8	11	1
2021-05-02T15:40:48.8999422Z > 9	13	2
2021-05-02T15:40:48.8999734Z > 10	17	4
2021-05-02T15:40:48.9000030Z > 11	11	1
2021-05-02T15:40:48.9000338Z > 12	13	2
2021-05-02T15:40:48.9000629Z > 13	17	4
2021-05-02T15:40:48.9000935Z > 14	11	1
2021-05-02T15:40:48.9001223Z > 15	13	2
2021-05-02T15:40:48.9001525Z > 16	17	4
2021-05-02T15:40:48.9001816Z > 17	11	1
2021-05-02T15:40:48.9002119Z > 18	13	2
2021-05-02T15:40:48.9002407Z > 19	17	4
2021-05-02T15:40:48.9002713Z > 20	11	1
2021-05-02T15:40:48.9003007Z > 21	13	2
2021-05-02T15:40:48.9003316Z > 22	17	4
2021-05-02T15:40:48.9004614Z diff /tmp/gh-ost-test.orig.content.csv /tmp/gh-ost-test.ghost.content.csv
2021-05-02T15:40:48.9099343Z + FAIL
2021-05-02T15:40:48.9136942Z ##[error]Process completed with exit code 1.

This will validate ongoing efforts to fix the issue.

[disser4]

I validated tonight that this code change works.

• I tested through the replica and inserted records while gh-ost was running and it did not return the integer, rather the enum value!
  Thank you for your work @shlomi-noach !!

[arthurschreiber]

❤️