node-api/common/jsonmap.go

101 lines
2.1 KiB
Go

package common
import (
"bytes"
"context"
"database/sql/driver"
"encoding/json"
"errors"
"fmt"
"strings"
"gorm.io/driver/mysql"
"gorm.io/gorm"
"gorm.io/gorm/clause"
"gorm.io/gorm/schema"
)
// JSONMap defined JSON data type, need to implements driver.Valuer, sql.Scanner interface
type JSONMap map[string]interface{}
// Value return json value, implement driver.Valuer interface
func (m JSONMap) Value() (driver.Value, error) {
if m == nil {
return nil, nil
}
ba, err := m.MarshalJSON()
return string(ba), err
}
// Scan scan value into Jsonb, implements sql.Scanner interface
func (m *JSONMap) Scan(val interface{}) error {
if val == nil {
*m = make(JSONMap)
return nil
}
var ba []byte
switch v := val.(type) {
case []byte:
ba = v
case string:
ba = []byte(v)
default:
return errors.New(fmt.Sprint("Failed to unmarshal JSONB value:", val))
}
t := map[string]interface{}{}
rd := bytes.NewReader(ba)
decoder := json.NewDecoder(rd)
decoder.UseNumber()
err := decoder.Decode(&t)
*m = t
return err
}
// MarshalJSON to output non base64 encoded []byte
func (m JSONMap) MarshalJSON() ([]byte, error) {
if m == nil {
return []byte("null"), nil
}
t := (map[string]interface{})(m)
return json.Marshal(t)
}
// UnmarshalJSON to deserialize []byte
func (m *JSONMap) UnmarshalJSON(b []byte) error {
t := map[string]interface{}{}
err := json.Unmarshal(b, &t)
*m = JSONMap(t)
return err
}
// GormDataType gorm common data type
func (m JSONMap) GormDataType() string {
return "jsonmap"
}
// GormDBDataType gorm db data type
func (JSONMap) GormDBDataType(db *gorm.DB, field *schema.Field) string {
switch db.Dialector.Name() {
case "sqlite3":
return "JSON"
case "mysql":
return "JSON"
case "postgres":
return "JSONB"
case "sqlserver":
return "NVARCHAR(MAX)"
}
return ""
}
func (jm JSONMap) GormValue(ctx context.Context, db *gorm.DB) clause.Expr {
data, _ := jm.MarshalJSON()
switch db.Dialector.Name() {
case "mysql":
if v, ok := db.Dialector.(*mysql.Dialector); ok && !strings.Contains(v.ServerVersion, "MariaDB") {
return gorm.Expr("CAST(? AS JSON)", string(data))
}
}
return gorm.Expr("?", string(data))
}