go 拼接sql

Posted 2022-10-12 lajiao

//原文链接:https://www.jianshu.com/p/a0569157c418
golang mysql拼接子查询

使用fmt.Sprintf拼接SQL
实例代码

func Select(ids []string) string 
    idStr := strings.Join(ids, "','")
    sqlText := "select id, name, age, created_at, updated_at from car where id in ('%s') limit %d"
    sqlText = fmt.Sprintf(sqlText, idStr, 20)
    return sqlText


func main() 
    sql := Select([]string"1", "2", "3")
    fmt.Println(sql)


//select id, name, age, created_at, updated_at from car where id ('1','2','3') limit 20
另一种写法,占位符实现
import (
    "strings"
    "database/sql"
)

func Select(db *sql.DB, ids []int) (err error) 
    //生成占位符?
    sqlText := "select * from car where id in ("+ strings.TrimRight(strings.Repeat("?,", len(ids)), ",")+")"
    var args []interface
    for _, v := range ids 
        args = append(args, v)
    
    row, err := db.Query(sqlText, args...)
    if err != nil 
        return
    
    defer row.Close()
    return