Method HasConstraint

migrator/migrator.go:789–805

HasConstraint check has constraint or not

(value interface{}, name string)

// HasConstraint check has constraint or not
func (m Migrator) HasConstraint(value interface{}, name string) bool {
	var count int64
	m.RunWithValue(value, func(stmt *gorm.Statement) error {
		currentDatabase := m.DB.Migrator().CurrentDatabase()
		constraint, table := m.GuessConstraintInterfaceAndTable(stmt, name)
		if constraint != nil {
			name = constraint.GetName()
		}

		return m.DB.Raw(
			"SELECT count(*) FROM INFORMATION_SCHEMA.table_constraints WHERE constraint_schema = ? AND table_name = ? AND constraint_name = ?",
			currentDatabase, table, name,
		).Row().Scan(&count)
	})

	return count > 0
}

// BuildIndexOptions build index options
func (m Migrator) BuildIndexOptions(opts []schema.IndexOption, stmt *gorm.Statement) (results []interface{}) {