package db

import (
	"database/sql"
	"strconv"
	"strings"
)

// 根据传入的字段列表生成相符数量的占位符
func GetPlaceholderByFields(fileds string) string {
	fileds = strings.Replace(fileds, " ", "", -1)
	fileds = strings.Trim(fileds, ",")
	count := len(strings.Split(fileds, ","))
	ret := make([]string, count)
	for i := 0; i < count; i++ {
		ret[i] = "?"
	}
	return strings.Join(ret, ",")
}

// Atoi 转换成整型
func Atoi(s string, d ...int) int {
	i, err := strconv.Atoi(s)
	if err != nil {
		if len(d) > 0 {
			return d[0]
		} else {
			return 0
		}
	}

	return i
}

// Atoi64 转换成整型int64
func Atoi64(s string, d ...int64) int64 {
	i, err := strconv.ParseInt(s, 10, 64)
	if err != nil {
		if len(d) > 0 {
			return d[0]
		} else {
			return 0
		}
	}

	return i
}

// 返回一个带有Null值的数据库字符串
func NewNullString(s string) sql.NullString {
	if len(s) == 0 {
		return sql.NullString{}
	}
	return sql.NullString{
		String: s,
		Valid:  true,
	}
}

// 返回一个带有Null值的数据库整形
func NewNullInt64(s int64, isNull bool) sql.NullInt64 {
	return sql.NullInt64{
		Int64: s,
		Valid: !isNull,
	}
}