Migrating from Mariadb/MySQL to PostgreSQL fails

[gzsombor]

• Gitea version (or commit ref): HEAD
• Git version:
• Operating system:
• Database (use [x]):
  • PostgreSQL
  • MySQL
  • MSSQL
  • SQLite
• Can you reproduce the bug at https://try.gitea.io:
  • Yes (provide example URL)
  • No
  • Not relevant
• Log gist:

Description

When generating sql dump from MariaDB/MySQL for PostgreSQL there are a couple of subtle errors in the output:

• it seems, that the boolean fields are returned as 'reflect.Slice', as byte('0') or byte('1') - which looks strange, and these values are outputted as 0/1, instead of what expected by PostgreSQL: false/true
• The sequences are initialized with this:

SELECT setval('table_id_seq', COALESCE((SELECT MAX(id) FROM "user"), 1), false);
SELECT setval('table_id_seq', COALESCE((SELECT MAX(id) FROM "public_key"), 1), false);
SELECT setval('table_id_seq', COALESCE((SELECT MAX(id) FROM "access_token"), 1), false);
SELECT setval('table_id_seq', COALESCE((SELECT MAX(id) FROM "repository"), 1), false);

• which is wrong, because 'table_id_seq' is not a valid sequence name
• with this initalization, the next call to nextval('action_id_seq') will return an ID which equals to the current maximum value, which cause index violations, and transaction rollback

[gzsombor]

Commit merged