客服系统即时通讯IM开发（六）Glang Gorm 执行原生Sql语句增删改查封装库【唯一客服】网站在线客服系统

package lib

import (
    "database/sql"
    "errors"
    "fmt"
    "github.com/jinzhu/gorm"
    _ "github.com/jinzhu/gorm/dialects/mysql"
    "io/ioutil"
    "log"
    "os"
    "strings"
    "time"
)

type DBTool struct {
    SqlPath                                    string
    Username, Password, Server, Port, Database string
}

func (this *DBTool) connect() (*gorm.DB, error) {
    dsn := fmt.Sprintf("%s:%s@tcp(%s:%s)/%s?charset=utf8mb4&parseTime=True&loc=Local", this.Username, this.Password, this.Server, this.Port, this.Database)
    db, err := gorm.Open("mysql", dsn)
    if err != nil {
        log.Println("数据库连接失败:", err)
        //panic("数据库连接失败!")
        return nil, err
    }
    db.SingularTable(true)
    db.LogMode(true)
    db.DB().SetMaxIdleConns(10)
    db.DB().SetMaxOpenConns(100)
    db.DB().SetConnMaxLifetime(59 * time.Second)
    return db, nil
}

//执行查询语句
func (this *DBTool) QuerySql(sqlStr string) ([]map[string]interface{}, error) {
    db, err := this.connect()
    var result []map[string]interface{}
    if err != nil {
        return result, err
    }
    sqlStr = strings.TrimSpace(sqlStr)
    if sqlStr == "" {
        return result, errors.New("sql语句为空")
    }
    rows, err := db.DB().Query(sqlStr)
    if err != nil {
        return result, err
    }

    //获取列名
    columns, _ := rows.Columns()

    //定义一个切片,长度是字段的个数,切片里面的元素类型是sql.RawBytes
    values := make([]sql.RawBytes, len(columns))
    //定义一个切片,元素类型是interface{} 接口
    scanArgs := make([]interface{}, len(values))
    for i := range values {
        //把sql.RawBytes类型的地址存进去了
        scanArgs[i] = &values[i]
    }
    //获取字段值
    for rows.Next() {
        res := make(map[string]interface{})
        rows.Scan(scanArgs...)
        for i, col := range values {
            res[columns[i]] = string(col)
        }
        result = append(result, res)
    }
    return result, nil
}

//执行增删改
func (this *DBTool) ExecuteSql(sql string) error {
    db, err := this.connect()
    sql = strings.TrimSpace(sql)
    if sql == "" {
        return errors.New("sql语句为空")
    }
    err = db.Exec(sql).Error
    if err != nil {
        log.Println("执行失败:" + err.Error())
        return err
    } else {
        log.Println(sql, "\t success!")
    }
    return nil
}

//执行sql文件
func (this *DBTool) ImportSql() error {
    _, err := os.Stat(this.SqlPath)
    if os.IsNotExist(err) {
        log.Println("数据库SQL文件不存在:", err)
        return err
    }

    db, err := this.connect()

    sqls, _ := ioutil.ReadFile(this.SqlPath)
    sqlArr := strings.Split(string(sqls), ";")
    for _, sql := range sqlArr {
        sql = strings.TrimSpace(sql)
        if sql == "" {
            continue
        }
        err := db.Exec(sql).Error
        if err != nil {
            log.Println("数据库导入失败:" + err.Error())
            return err
        } else {
            log.Println(sql, "\t success!")
        }
    }
    return nil
}

    db := &DBTool{
        Username: "BT_DB_USERNAME",
        Password: "BT_DB_PASSWORD",
        Server:   "127.0.0.1",
        Port:     "3306",
        Database: "BT_DB_NAME",
    }
    res, err := db.QuerySql("select * from user")
    log.Println(res, err)