package Model

import (
	"dsSso/Const/ErrorConst"
	"dsSso/Utils/CommonUtil"
	"dsSso/Utils/DbUtil"
	"dsSso/Utils/LogUtil"
	"dsSso/Utils/RedisUtil"
	"time"
)

var db=DbUtil.Engine
/**
功能：用于将interface转为struct的结构体
作者：黄海
时间：2020-02-05
*/
type Selector struct {
	TableName   string
	PkField     string
	RedisPrefix string
}

/**
功能：注册一个函数，用于提取计算指定数据表对应的相关信息
作者：黄海
时间：2020-03-27
*/
func (m *Selector) Get(tableName string) (bool, Selector) {
	m.TableName = tableName
	m.RedisPrefix = CommonUtil.GetSnakeCaseStr(tableName) + ":"
	var success = true
	success, m.PkField =GetTablePk(tableName)
	return success, *m
}


/**
功能：获取指定表的主键
作者：黄海
时间：2020-03-26
*/
func GetTablePk(tableName string) (bool, string) {
	//优先到缓存中查找
	key := "pk_" + tableName
	pk, err := RedisUtil.GET(key)
	if err != nil {
		sql := "select column_name from information_schema.`key_column_usage` where table_name=? and constraint_name='primary'"
		list, err := db.SQL(sql, tableName).Query().List()
		if err != nil || len(list) == 0 {
			LogUtil.Error(ErrorConst.SqlQueryError, err.Error())
			return false, ""
		}
		pk = list[0]["column_name"].(string)
		//设置缓存
		RedisUtil.SET(key, pk, 24*7*time.Hour)
	}
	return true, pk
}