gorm/association.go

256 lines
9.5 KiB
Go

package gorm
import (
"fmt"
"reflect"
)
// Association Association Mode contains some helper methods to handle relationship things easily.
type Association struct {
Scope *Scope
Column string
Error error
Field *Field
}
// Find find out all related associations
func (association *Association) Find(value interface{}) *Association {
association.Scope.related(value, association.Column)
return association.setErr(association.Scope.db.Error)
}
// Append append new associations for many2many, has_many, will replace current association for has_one, belongs_to
func (association *Association) Append(values ...interface{}) *Association {
if relationship := association.Field.Relationship; relationship.Kind == "has_one" {
return association.Replace(values...)
}
return association.saveAssociations(values...)
}
// Replace replace current associations with new one
func (association *Association) Replace(values ...interface{}) *Association {
var (
relationship = association.Field.Relationship
scope = association.Scope
field = association.Field.Field
newDB = scope.NewDB()
)
// Append new values
association.Field.Set(reflect.Zero(association.Field.Field.Type()))
association.saveAssociations(values...)
// Belongs To
if relationship.Kind == "belongs_to" {
// Set foreign key to be null when clearing value (length equals 0)
if len(values) == 0 {
// Set foreign key to be nil
var foreignKeyMap = map[string]interface{}{}
for _, foreignKey := range relationship.ForeignDBNames {
foreignKeyMap[foreignKey] = nil
}
association.setErr(newDB.Model(scope.Value).UpdateColumn(foreignKeyMap).Error)
}
} else {
// Polymorphic Relations
if relationship.PolymorphicDBName != "" {
newDB = newDB.Where(fmt.Sprintf("%v = ?", scope.Quote(relationship.PolymorphicDBName)), scope.TableName())
}
// Relations except new created
if len(values) > 0 {
var associationForeignFieldNames []string
if relationship.Kind == "many_to_many" {
associationForeignFieldNames = relationship.AssociationForeignFieldNames
} else {
associationForeignFieldNames = relationship.AssociationForeignDBNames
}
newPrimaryKeys := association.getPrimaryKeys(associationForeignFieldNames, field.Interface())
if len(newPrimaryKeys) > 0 {
sql := fmt.Sprintf("%v NOT IN (%v)", toQueryCondition(scope, relationship.AssociationForeignDBNames), toQueryMarks(newPrimaryKeys))
newDB = newDB.Where(sql, toQueryValues(newPrimaryKeys)...)
}
}
if relationship.Kind == "many_to_many" {
if sourcePrimaryKeys := association.getPrimaryKeys(relationship.ForeignFieldNames, scope.Value); len(sourcePrimaryKeys) > 0 {
newDB = newDB.Where(fmt.Sprintf("%v IN (%v)", toQueryCondition(scope, relationship.ForeignDBNames), toQueryMarks(sourcePrimaryKeys)), toQueryValues(sourcePrimaryKeys)...)
association.setErr(relationship.JoinTableHandler.Delete(relationship.JoinTableHandler, newDB, relationship))
}
} else if relationship.Kind == "has_one" || relationship.Kind == "has_many" {
var foreignKeyMap = map[string]interface{}{}
for idx, foreignKey := range relationship.ForeignDBNames {
foreignKeyMap[foreignKey] = nil
if field, ok := scope.FieldByName(relationship.AssociationForeignFieldNames[idx]); ok {
newDB = newDB.Where(fmt.Sprintf("%v = ?", scope.Quote(foreignKey)), field.Field.Interface())
}
}
fieldValue := reflect.New(association.Field.Field.Type()).Interface()
association.setErr(newDB.Model(fieldValue).UpdateColumn(foreignKeyMap).Error)
}
}
return association
}
// Delete remove relationship between source & passed arguments, but won't delete those arguments
func (association *Association) Delete(values ...interface{}) *Association {
var (
relationship = association.Field.Relationship
scope = association.Scope
field = association.Field.Field
newDB = scope.NewDB()
)
if len(values) == 0 {
return association
}
var deletingResourcePrimaryFieldNames, deletingResourcePrimaryDBNames []string
for _, field := range scope.New(reflect.New(field.Type()).Interface()).Fields() {
if field.IsPrimaryKey {
deletingResourcePrimaryFieldNames = append(deletingResourcePrimaryFieldNames, field.Name)
deletingResourcePrimaryDBNames = append(deletingResourcePrimaryDBNames, field.DBName)
}
}
deletingPrimaryKeys := scope.getColumnAsArray(deletingResourcePrimaryFieldNames, values...)
if relationship.Kind == "many_to_many" {
// source value's foreign keys
for idx, foreignKey := range relationship.ForeignDBNames {
if field, ok := scope.FieldByName(relationship.ForeignFieldNames[idx]); ok {
newDB = newDB.Where(fmt.Sprintf("%v = ?", scope.Quote(foreignKey)), field.Field.Interface())
}
}
// association value's foreign keys
deletingPrimaryKeys := association.getPrimaryKeys(relationship.AssociationForeignFieldNames, values...)
sql := fmt.Sprintf("%v IN (%v)", toQueryCondition(scope, relationship.AssociationForeignDBNames), toQueryMarks(deletingPrimaryKeys))
newDB = newDB.Where(sql, toQueryValues(deletingPrimaryKeys)...)
association.setErr(relationship.JoinTableHandler.Delete(relationship.JoinTableHandler, newDB, relationship))
} else {
var foreignKeyMap = map[string]interface{}{}
for _, foreignKey := range relationship.ForeignDBNames {
foreignKeyMap[foreignKey] = nil
}
if relationship.Kind == "belongs_to" {
// find with deleting relation's foreign keys
primaryKeys := scope.getColumnAsArray(relationship.AssociationForeignFieldNames, values...)
newDB = newDB.Where(
fmt.Sprintf("%v IN (%v)", toQueryCondition(scope, relationship.ForeignDBNames), toQueryMarks(primaryKeys)),
toQueryValues(primaryKeys)...,
)
// set foreign key to be null
modelValue := reflect.New(scope.GetModelStruct().ModelType).Interface()
if results := newDB.Model(modelValue).UpdateColumn(foreignKeyMap); results.Error == nil {
if results.RowsAffected > 0 {
scope.updatedAttrsWithValues(foreignKeyMap, false)
}
} else {
association.setErr(results.Error)
}
} else if relationship.Kind == "has_one" || relationship.Kind == "has_many" {
// find all relations
primaryKeys := scope.getColumnAsArray(relationship.AssociationForeignFieldNames, scope.Value)
newDB = newDB.Where(
fmt.Sprintf("%v IN (%v)", toQueryCondition(scope, relationship.ForeignDBNames), toQueryMarks(primaryKeys)),
toQueryValues(primaryKeys)...,
)
// only include those deleting relations
newDB = newDB.Where(
fmt.Sprintf("%v IN (%v)", toQueryCondition(scope, deletingResourcePrimaryDBNames), toQueryMarks(deletingPrimaryKeys)),
toQueryValues(deletingPrimaryKeys)...,
)
// set matched relation's foreign key to be null
fieldValue := reflect.New(association.Field.Field.Type()).Interface()
association.setErr(newDB.Model(fieldValue).UpdateColumn(foreignKeyMap).Error)
}
}
// Remove deleted records from field
if association.Error == nil {
if association.Field.Field.Kind() == reflect.Slice {
leftValues := reflect.Zero(association.Field.Field.Type())
for i := 0; i < association.Field.Field.Len(); i++ {
reflectValue := association.Field.Field.Index(i)
primaryKey := association.getPrimaryKeys(deletingResourcePrimaryFieldNames, reflectValue.Interface())[0]
var included = false
for _, pk := range deletingPrimaryKeys {
if equalAsString(primaryKey, pk) {
included = true
}
}
if !included {
leftValues = reflect.Append(leftValues, reflectValue)
}
}
association.Field.Set(leftValues)
} else if association.Field.Field.Kind() == reflect.Struct {
primaryKey := association.getPrimaryKeys(deletingResourcePrimaryFieldNames, association.Field.Field.Interface())[0]
for _, pk := range deletingPrimaryKeys {
if equalAsString(primaryKey, pk) {
association.Field.Set(reflect.Zero(association.Field.Field.Type()))
break
}
}
}
}
return association
}
// Clear remove relationship between source & current associations, won't delete those associations
func (association *Association) Clear() *Association {
return association.Replace()
}
// Count return the count of current associations
func (association *Association) Count() int {
var (
count = 0
relationship = association.Field.Relationship
scope = association.Scope
fieldValue = association.Field.Field.Interface()
newScope = scope.New(fieldValue)
)
if relationship.Kind == "many_to_many" {
relationship.JoinTableHandler.JoinWith(relationship.JoinTableHandler, scope.DB(), association.Scope.Value).Model(fieldValue).Count(&count)
} else if relationship.Kind == "has_many" || relationship.Kind == "has_one" {
query := scope.DB()
for idx, foreignKey := range relationship.ForeignDBNames {
if field, ok := scope.FieldByName(relationship.AssociationForeignDBNames[idx]); ok {
query = query.Where(fmt.Sprintf("%v.%v = ?", newScope.QuotedTableName(), scope.Quote(foreignKey)),
field.Field.Interface())
}
}
if relationship.PolymorphicType != "" {
query = query.Where(fmt.Sprintf("%v.%v = ?", newScope.QuotedTableName(), newScope.Quote(relationship.PolymorphicDBName)), scope.TableName())
}
query.Model(fieldValue).Count(&count)
} else if relationship.Kind == "belongs_to" {
query := scope.DB()
for idx, primaryKey := range relationship.AssociationForeignDBNames {
if field, ok := scope.FieldByName(relationship.ForeignDBNames[idx]); ok {
query = query.Where(fmt.Sprintf("%v.%v = ?", newScope.QuotedTableName(), scope.Quote(primaryKey)),
field.Field.Interface())
}
}
query.Model(fieldValue).Count(&count)
}
return count
}