go 拼接sql

//原文鏈接:https://www.jianshu.com/p/a0569157c418
golang mysql拼接子查詢

使用fmt.Sprintf拼接SQL
實例代碼

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
另一種寫法,占位符實現
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
}