beego从入门到弃坑（ 四 ）数据库连接以及构造器使用

beego框架对数据库的链接，如果你只是把数据库连接写到配置文件里，是不起任何人作用的，对于用习惯了laravel框架的我来说是非常坑的一件事。
具体的链接只需要在入口文件添加

package main

import (
    _ "achievement/routers"
    
    
    _ 
)

func init() {
//设置日志文件
    beego.SetLogger("file", `{"filename":"logs/beego.log"}`)
//设置数据库的配制
    orm.RegisterDataBase("default","mysql","root:123456@tcp(127.0.0.1:3306)/ssms?charset=utf8")
    beego.BConfig.WebConfig.Session.SessionOn = true
}

func main() {
    beego.Run();
}

构造器

在beego文档对构造器的描述非常的少只有一个方法的描述，所以很多东西我们不得不一边看源码，一边尝试这些方法的作用。
源码中方法展示

type QueryBuilder interface {
    Select(fields ...string) QueryBuilder
    ForUpdate() QueryBuilder
    From(tables ...string) QueryBuilder
    InnerJoin(table string) QueryBuilder
    LeftJoin(table string) QueryBuilder
    RightJoin(table string) QueryBuilder
    
    Where(cond string) QueryBuilder
    And(cond string) QueryBuilder
    Or(cond string) QueryBuilder
    In(vals ...string) QueryBuilder
    OrderBy(fields ...string) QueryBuilder
    Asc() QueryBuilder
    Desc() QueryBuilder
    Limit(limit int) QueryBuilder
    Offset(offset int) QueryBuilder
    GroupBy(fields ...string) QueryBuilder
    Having(cond string) QueryBuilder
    Update(tables ...string) QueryBuilder
    Set(kv ...string) QueryBuilder
    Delete(tables ...string) QueryBuilder
    InsertInto(table string, fields ...string) QueryBuilder
    Values(vals ...string) QueryBuilder
    Subquery(sub string, alias string) string
    String() string
}

查询语句

func (u *User)LoginJudge(account string,password string)  []User {
    var users []User
    qb,_:=orm.NewQueryBuilder("mysql")
    // 构建查询对象
    qb.Select("user.account").
        From("user").
        Where("account = ?").
        And("password = ?").And("type != 2")
    //返回sql语句
    sql := qb.String()
    // 执行 SQL 语句
    o := orm.NewOrm()
    o.Raw(sql,account,password).QueryRows(&users)
    return users
}

beego的查询语句可以根据条件拼接

//查询学生的成绩
func (this *Score)SelectAll(page,limit, class int,school string) []ScoreInformation {
    var score []ScoreInformation
    page = (page-1)*10
    qb,_ := orm.NewQueryBuilder("mysql")
    qb.Select("student.number","student.name","student.sex","clazz.clazz_name","grade.grade_name","escore.score","course.name as course_name","exam.exam_name","exam.time").
        From("student,clazz,grade,escore,course,exam").
        Where("student.clazzid = clazz.id").
        And("student.gradeid = grade.id").
        And("student.id = escore.studentid").
        And("escore.courseid = course.id").
        And("exam.id = escore.examid")

    if class != -1 {
        qb.And("clazz.id = "+strconv.Itoa(class))
    }
    if school != ""{
        qb.And("student.number = "+school)
    }
    qb.Limit(limit).
        Offset(page)
    sql := qb.String()
    fmt.Println(sql)
    o := orm.NewOrm()
    _,error:=o.Raw(sql).QueryRows(&score)
    fmt.Println(error)
    fmt.Println(score)
    return score
}

插入语句

func (u *User)AddMenager(account,password,name string) error  {
    qb,_:=orm.NewQueryBuilder("mysql")
    // 构建查询对象
    qb.InsertInto("user","user.account","user.password","user.name","user.type").
        Values("?","?","?","?")
    //返回sql语句
    sql := qb.String()
    fmt.Println(sql)
    // 执行 SQL 语句
    o := orm.NewOrm()
    _,error := o.Raw(sql,account,password,name,3).Exec()
    return error
}

删除语句

func (u *User)DeleteMenagerConut(id int) error  {
    qb,_:=orm.NewQueryBuilder("mysql")
    // 构建查询对象
    qb.Delete("user").
        From("user").
        Where("id = ?")
    //返回sql语句
    sql := qb.String()
    fmt.Println(sql)
    // 执行 SQL 语句
    o := orm.NewOrm()
    _,error := o.Raw(sql,id).Exec()
    return error
}