New migrations are generated if one adds a constraint expression written in lowercase without using parentheses

[JasonRammoray]

Describe the bug
If one adds a constraint using Check decorator and provides a simple expression, like logical one, and written in lowercase without using parentheses, then migration:create will continue generating the same migration even after migration:up has been applied.
The subsequent migration, however, is not generated if one uses uppercase for sql keywords (for example, IS NOT NULL, OR).

Stack trace
None

To Reproduce
Steps to reproduce the behavior:

1. Create an entity with two nullable fields
2. Create a constraint for that entity as:

@Check<EntityTypeHere>({
  expression: columns => `${column.<firstColumnNameHere>} is not null or ${column.<secondColumnNameHere>} is not null`,
  name: '<some_name_here>'
})

3. Generate a migration
4. Migrate to that migration
5. Try generating a migration one more time

Expected behavior
No second migration should be created given there were no changes to the entity model.

Observations
It appears if one wraps every expression in parentheses and writes sql keywords in caps, then the issue isn't reproducible.
E.g:

@Check<EntityTypeHere>({
  expression: columns => `(${column.<firstColumnNameHere>} IS NOT NULL) OR (${column.<secondColumnNameHere>} IS NOT NULL)`,
  name: '<some_name_here>',
})

Versions

Dependency	Version
node	16.16.0
typescript	4.8.4
mikro-orm	5.5.3
your-driver	postgresql (5.5.3)

[B4nan]

Interesting, I guess postgres normalizes the query and store that instead of the expression provided by you. Will try to find some way to get around this, worst case we could compare the expression as lower case and ignore parens, could be good enough heuristic about what changed.