go-gorm/gorm · error

preload is not allowed when count is used

Error message

preload is not allowed when count is used

What it means

Error "preload is not allowed when count is used" thrown in go-gorm/gorm.

Source

Thrown at errors.go:47

	ErrInvalidData = errors.New("unsupported data")
	// ErrUnsupportedDriver unsupported driver
	ErrUnsupportedDriver = errors.New("unsupported driver")
	// ErrRegistered registered
	ErrRegistered = errors.New("registered")
	// ErrInvalidField invalid field
	ErrInvalidField = errors.New("invalid field")
	// ErrEmptySlice empty slice found
	ErrEmptySlice = errors.New("empty slice found")
	// ErrDryRunModeUnsupported dry run mode unsupported
	ErrDryRunModeUnsupported = errors.New("dry run mode unsupported")
	// ErrInvalidDB invalid db
	ErrInvalidDB = errors.New("invalid db")
	// ErrInvalidValue invalid value
	ErrInvalidValue = errors.New("invalid value, should be pointer to struct or slice")
	// ErrInvalidValueOfLength invalid values do not match length
	ErrInvalidValueOfLength = errors.New("invalid association values, length doesn't match")
	// ErrPreloadNotAllowed preload is not allowed when count is used
	ErrPreloadNotAllowed = errors.New("preload is not allowed when count is used")
	// ErrDuplicatedKey occurs when there is a unique key constraint violation
	ErrDuplicatedKey = errors.New("duplicated key not allowed")
	// ErrForeignKeyViolated occurs when there is a foreign key constraint violation
	ErrForeignKeyViolated = errors.New("violates foreign key constraint")
	// ErrCheckConstraintViolated occurs when there is a check constraint violation
	ErrCheckConstraintViolated = errors.New("violates check constraint")
)

View on GitHub (pinned to 1d6ce99528)

Solutions

1. Remove Preload calls when chaining Count, e.g. db.Model(&User{}).Where(...).Count(&n).
2. Run the Count query separately from the preloading query.
3. Use Select with subqueries instead of Preload when you also need counts.

Example fix

Do not combine Preload with Count; run the count on a separate session: db.Session(&gorm.Session{}).Count(&n)

When it happens

Trigger: Thrown at errors.go:47 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of go-gorm/gorm@1d6ce99528 (2026-08-15). Data as JSON: /api/errors/4927c66e9c33f1bb. Report an issue: GitHub.