fix: support sharding sql with alias in where clause

[a631807682]

• Do only one thing
• Non breaking API changes
• Tested

What did this pull request do?

When we use db.Preload, it will generate sql with alias like:

SELECT * FROM "orders" WHERE "orders"."user_id" = 1

The expr parsed by sql is sqlparser.QualifiedRef which is not supported and will return ErrMissingShardingKey
This feat will replace sql like this:

SELECT * FROM "orders_1" as "orders" WHERE "orders"."user_id" = 1

User Case Description

[a631807682]

related to go-gorm/gorm#5301
will not panic in next gorm version
test will pass when #34 merged.

[ifooth]

Any Update?, Support for the sqlparser.QualifiedRef feature is quite needed