golang mysql封装

package models

import (
    "database/sql"
    "errors"
    . "gin_monitor/config"
    "strings"
    // "fmt"
    _ "github.com/go-sql-driver/mysql"
)

//数据库连接DSN
const (
    DbType = "mysql"
    // DefaultConn = "root:system@tcp(172.16.4.51:3306)/monitor?charset=utf8"
)

//mysql动态连接池
var db *sql.DB
var DefaultConn string

//连接数据库基本数据字典
type Info struct {
    username string
    password string
    host     string
    port     string
    dbname   string
    charset  string
}

func CheckErr(err error) {
    if err != nil {
        panic(err)
    }
}

func init() {
    //获取配置文件
    info := Info{}
    info.username = GetConfig("mysql", "username")
    info.password = GetConfig("mysql", "password")
    info.host = GetConfig("mysql", "host")
    info.port = GetConfig("mysql", "port")
    info.dbname = GetConfig("mysql", "dbname")
    info.charset = GetConfig("mysql", "charset")
    //组装MYSQL连接DSN连接
    DefaultConn = info.username + ":" + info.password + "@tcp(" + info.host + ":" + info.port + ")/" + info.dbname + "?charset=" + info.charset
    // "初始化数据库连接池"
    db, _ = sql.Open(DbType, DefaultConn)
    db.SetMaxOpenConns(2000)
    db.SetMaxIdleConns(1000)
    db.Ping()
}

//定义一个接口，只要实现了这个接口的方法就可以调用这个接口
type Db interface {
    //http://127.0.0.1/mysql/query?sql=select host,type,table_schema,table_name,table_rows,table_size_m,index_size_m,sysdates from monitorss order by index_size_m desc limit 100
    Query() (map[int]map[string]string, error)
    //http://172.16.4.51/mysql/update?table=tttt&set=name:lxp&where=id:1
    Update() error
    // http://127.0.0.1/mysql/insert?table=ttt&data=name:lixueping,id:1
    Insert() error
    // http://127.0.0.1/mysql/delete?table=ttt&where=id:1
    Delete() error
}

//定义mysql结构，条件全部满足后就可以实现接口方法
type Mysql struct {
    Sql string
    //table->map[string]string  data->map[string]map[string]string
    Data map[string]interface{}
}

type Oracle struct {
    Username, Password, Host, Port, Db, Sql string
}

type Mongodb struct {
    Username, Password, Host, Port, Db, Sql string
}

//实现mysql的db接口
//"root:password@tcp(127.0.0.1:3306)/monitor?charset=utf8"
func (m Mysql) Query() (map[int]map[string]string, error) {
    //通过数据库连接池db
    rows, err := db.Query(m.Sql)
    if err != nil {
        return nil, errors.New("\n查询" + m.Sql + "失败,原因:\n" + err.Error())
    }
    defer rows.Close()
    //字典类型
    //构造scanArgs、values两个数组，scanArgs的每个值指向values相应值的地址
    columns, _ := rows.Columns()
    scanArgs := make([]interface{}, len(columns))
    values := make([]sql.RawBytes, len(columns))
    for i := range values {
        scanArgs[i] = &values[i]
    }

    //最后得到的map
    results := make(map[int]map[string]string)
    i := 0
    for rows.Next() {
        //将行数据保存到record字典
        err = rows.Scan(scanArgs...)
        if err != nil {
            return nil, errors.New("结果组装失败,原因:\n" + err.Error())
        }
        row := make(map[string]string)
        for k, v := range values {
            key := columns[k]
            row[key] = string(v)
        }
        results[i] = row
        i++

    }
    return results, nil
}

func (m Mysql) Insert() error {
    //m.Data由table和data构成
    //初始化一个结果集
    args := make([]interface{}, len(m.Data["data"].(map[string]string)))
    hosts := "("
    //统计次数
    count := 0
    //组装结果集和sql
    for k, v := range m.Data["data"].(map[string]string) {
        args[count] = v
        count++
        if count != len(m.Data["data"].(map[string]string)) {
            hosts += k + ","
        } else {
            hosts += k + ")"
        }

    }
    sqlScript := "INSERT INTO " + m.Data["table"].(string) + " " + hosts + " VALUES (?" + strings.Repeat(",?", len(m.Data["data"].(map[string]string))-1) + ")"
    // println(sqlScript)
    /*
        println(sqlScript, args)
        _, err := db.Query(sqlScript, args...)
        由于自带的insert比如写死参数，无法动态调配，所以换成组装SQL的形式，以下代码留着学习
    */

    stmt, err := db.Prepare(sqlScript)
    defer stmt.Close()
    if err != nil {
        return errors.New(sqlScript + " 字段不存在或者数据不正确！")
    }
    _, err = stmt.Exec(args...)
    CheckErr(err)

    return err
}

func (m Mysql) Update() error {
    //m.Data由table、set和where构成
    //初始化一个结果集
    args := make([]interface{}, len(m.Data["set"].(map[string]string))+len(m.Data["where"].(map[string]string)))
    //统计次数
    count := 0
    c_where := 0
    //组装结果集set和where
    set := " SET "
    where := " WHERE "
    for k, v := range m.Data["set"].(map[string]string) {
        args[count] = v
        count++
        if count != len(m.Data["set"].(map[string]string)) {
            set += k + "=?, "
        } else {
            set += k + "=? "
        }
    }

    for kk, vv := range m.Data["where"].(map[string]string) {
        args[count] = vv
        count++
        c_where++
        if len(m.Data["where"].(map[string]string)) == 1 {
            where += kk + "=?"
        } else if c_where != len(m.Data["where"].(map[string]string)) && len(m.Data["where"].(map[string]string)) != 1 {
            where += kk + "=? and "
        } else if c_where == len(m.Data["where"].(map[string]string)) {
            where += kk + "=? "
        }
    }

    sqlScript := "UPDATE " + m.Data["table"].(string) + set + where
    // println(sqlScript)
    /*
        println(sqlScript, args)
        _, err := db.Query(sqlScript, args...)
        由于自带的insert比如写死参数，无法动态调配，所以换成组装SQL的形式，以下代码留着学习
    */

    stmt, err := db.Prepare(sqlScript)
    defer stmt.Close()
    if err != nil {
        return errors.New(sqlScript + " 字段不存在或者数据不正确！")
    }
    _, err = stmt.Exec(args...)
    CheckErr(err)

    return err
}

func (m Mysql) Delete() error {
    //m.Data由table和where构成
    //初始化一个结果集
    args := make([]interface{}, len(m.Data["where"].(map[string]string)))
    //统计次数
    count := 0
    //组装结果集set和where
    where := " WHERE "

    for kk, vv := range m.Data["where"].(map[string]string) {
        args[count] = vv
        count++
        if len(m.Data["where"].(map[string]string)) == 1 {
            where += kk + "=?"
        } else if count != len(m.Data["where"].(map[string]string)) && len(m.Data["where"].(map[string]string)) != 1 {
            where += kk + "=? and "
        } else if count == len(m.Data["where"].(map[string]string)) {
            where += kk + "=? "
        }
    }

    sqlScript := "DELETE FROM " + m.Data["table"].(string) + where
    // println(sqlScript)
    /*
        println(sqlScript, args)
        _, err := db.Query(sqlScript, args...)
        由于自带的insert比如写死参数，无法动态调配，所以换成组装SQL的形式，以下代码留着学习
    */

    stmt, err := db.Prepare(sqlScript)
    defer stmt.Close()
    if err != nil {
        return errors.New(sqlScript + " 字段不存在或者数据不正确！")
    }
    _, err = stmt.Exec(args...)
    CheckErr(err)

    return err

}