package main

import (
	"database/sql"
	"fmt"
	"log"

	_ "github.com/godror/godror"
)

type str_item struct {
	item_cd string
	item_nm string
}

type str_item_ls struct {
	str_item []str_item
}

func (item_ls *str_item_ls) AddItem(item str_item) []str_item {
	item_ls.str_item = append(item_ls.str_item, item)
	return item_ls.str_item
}

func get_list(sql_str string, item_cnt int, item_list *str_item_ls, c chan bool) {
	// 본인 계정에 맞는 접속 정보
	db, err := sql.Open("godror", "db_account/db_password@db_name")
	db.SetMaxOpenConns(5)
	db.SetMaxIdleConns(3)
	if err != nil {
		fmt.Println(err)
		return
	}
	defer db.Close()

	conn, err := db.Query(sql_str, item_cnt)
	if err != nil {
		fmt.Println(err)
		return
	}
	defer conn.Close()

	item := new(str_item)

	var item_cd string
	var item_nm string

	for conn.Next() {
		err := conn.Scan(&item_cd, &item_nm)
		if err != nil {
			log.Fatal(err)
		}

		item.item_cd = item_cd
		item.item_nm = item_nm
		item_list.AddItem(*item)
	}

	c <- true
}

func main() {
	c := make(chan bool)
	item_list := new(str_item_ls)
	// 본인 DB 테이블 조회 
	go get_list("select tname,tabtype from tab where substr(tname,1,1) in ('A','B','C','D','E','F','G','H','I') and rownum <= :val", 6, item_list, c)
	go get_list("select tname,tabtype from tab where substr(tname,1,1) in ('J','K','L','M','N','O','P','Q','R') and rownum <= :val", 6, item_list, c)
	go get_list("select tname,tabtype from tab where substr(tname,1,1) in ('S','T','U','V','W','X','Y','Z') and rownum <= :val", 6, item_list, c)

	for i := 0; i < 3; i++ {
		fmt.Println(<-c)
	}

	for i, s := range item_list.str_item {
		fmt.Println(s.item_cd, s.item_nm, i)
	}
}