mindxdl---common---db_handler.go

// Copyright (c) 2021. Huawei Technologies Co., Ltd. All rights reserved.

// Package common this file for db handler
package common

import (
   "github.com/jinzhu/gorm"
   _ "github.com/jinzhu/gorm/dialects/mysql" // mysql driver
   "huawei.com/npu-exporter/hwlog"
   "sync"
)

const (
   // DBType db type
   DBType = "mysql"
   // DBSecretName  the secret name which contains db connection path
   DBSecretName = "mysql-secret"
   // DBSecretNameSpace  the namespace for secret which contains db connection path
   DBSecretNameSpace = "mindx-dl"
   // GetDBSecretRetryCount retry count for getting secret
   GetDBSecretRetryCount = 10
   // GetDBSecretTimeInterval interval for getting secret, unit: second
   GetDBSecretTimeInterval = 5
   // DBSecretConnectionPathKey db connection path key in secret
   DBSecretConnectionPathKey = "connection-path"
   // DBTableOption db table option
   DBTableOption = "gorm:table_options"
   // InnoDBEngine innodb engine
   InnoDBEngine = "ENGINE=InnoDB"
)

var dbOnce sync.Once

// DbCommonHandler db handler
type DbCommonHandler struct {
   db     *gorm.DB
   dbType string
   dbPath string
}

// NewDBInstance create db instance
func NewDBInstance(dbType, dbPath string) *DbCommonHandler {
   handler := &DbCommonHandler{
      dbType: dbType,
      dbPath: dbPath,
   }

   return handler
}

func (handler *DbCommonHandler) initDBInstance() {
   dbase, err := gorm.Open(handler.dbType, handler.dbPath)
   if err != nil {
      hwlog.RunLog.Fatal(err)
   }
   hwlog.RunLog.Info("connect to db success")
   handler.db = dbase
}

// GetDB return db instance
func (handler *DbCommonHandler) GetDB() *gorm.DB {
   dbOnce.Do(handler.initDBInstance)
   return handler.db
}

// CloseDB close db connection
func (handler *DbCommonHandler) CloseDB() {
   if handler.db == nil {
      return
   }

   if err := handler.db.Close(); err != nil {
      hwlog.RunLog.Error(err)
   }
}

// SetScopes set scopes
func (handler *DbCommonHandler) SetScopes(scopes ...func(db *gorm.DB) *gorm.DB) *gorm.DB {
   return handler.GetDB().Scopes(scopes...)
}

// SetPager return pager
func (handler *DbCommonHandler) SetPager(page, pageSize uint64) func(db *gorm.DB) *gorm.DB {
   return func(db *gorm.DB) *gorm.DB {
      offset := (page - 1) * pageSize
      return db.Offset(offset).Limit(pageSize)
   }
}

// SetQueryFields set query field
func (handler *DbCommonHandler) SetQueryFields(fieldsNameList interface{}) func(db *gorm.DB) *gorm.DB {
   return func(db *gorm.DB) *gorm.DB {
      return db.Select(fieldsNameList)
   }
}

// SetModel set query table
func (handler *DbCommonHandler) SetModel(model interface{}) func(db *gorm.DB) *gorm.DB {
   return func(db *gorm.DB) *gorm.DB {
      return db.Model(model)
   }
}

// SetJoins set joins
func (handler *DbCommonHandler) SetJoins(query string, values ...interface{}) func(db *gorm.DB) *gorm.DB {
   return func(db *gorm.DB) *gorm.DB {
      return db.Joins(query, values...)
   }
}

// QueryAll query all data
func (handler *DbCommonHandler) QueryAll(db *gorm.DB, outPut, condition interface{}, param ...interface{}) *gorm.DB {
   return db.Where(condition, param...).Find(outPut)
}

// First return the fist match data
func (handler *DbCommonHandler) First(db *gorm.DB, outPut, condition interface{}, param ...interface{}) *gorm.DB {
   return db.Where(condition, param...).First(outPut)
}

mindxdl---common---db_handler.go的相关教程结束。