Filter db rows with GORM preload - database

Question

Currently, I got this struct
type Token struct {
gorm.Model
Name string `gorm:"column:name"`
Enabled bool `gorm:"column:enabled"`
Symbol string `gorm:"column:symbol"`
TokenDetails []*EarnTokenDetail `gorm:"foreignkey:TokenID;references:ID"`
}
type EarnTokenDetail struct {
gorm.Model
Name string `gorm:"column:name"`
TokenID uint64 `gorm:"column:token_id"`
Enabled bool `gorm:"column:enabled"`
Chains *EarnChain `gorm:"foreignkey:ID;references:ChainID"`
}
type EarnChain struct {
ID uint64 `gorm:"primary_key column:id"`
Enabled bool `gorm:"column:enabled"`
Name string `gorm:"column:name"`
}
And this GORM query:
var tokens []*model.Token
result := e.db.
WithContext(ctx).
Preload("TokenDetails", "token_details.enabled = true").
Preload("TokenDetails.Chains", "chains.enabled = true").
Find(&tokens, "tokens.enabled = true")
It works fine when everything is enabled, but when I disable chains in the database, the result will still show the tokens with disabled chains, with the Chains field empty.
How can I filter out those rows while still using preload?

Answer 1

According the the GORM documentation, that's the expected behavior. It does one query after another, so there is no way to "drop" results of the former queries. If you don't want these results at all - not even with an empty Chain field, consider to use Join() to filter out those. I think I even found a comment pointing that out: How to multiple table joins in GORM