mysql数据导出golang实现

mysql数据导出为excel文件，golang实现：

首先下载依赖到的三方库：

Simple install the package to your $GOPATH with the go tool from shell:

$ go get -u github.com/go-sql-driver/mysql

具体说明请看：
库地址
wiki说明

代码示例如下，用到了go的flag包的能力，传入命令行参数。具体看helpInfo：

Usage of mysqldataexport:
  -port int
        the port for mysql,default:32085
  -addr string
        the address for mysql,default:10.146.145.67
  -user string
        the username for login mysql,default:dbuser

  -pwd  string
        the password for login mysql by the username,default:Admin@123
  -db   string
        the port for me to listen on,default:auditlogdb
  -tables string
        the tables will export data, multi tables separator by comma, default:op_log,sc_log,sys_log

代码：

package main

// 从Mysql中导出数据到CSV文件。

import (
    "database/sql"
    "encoding/csv"
    "fmt"
    "os"
    _ "github.com/go-sql-driver/mysql"
    "flag"
    "strings"
)

var (
    tables         = make([]string, 0)
    dataSourceName = ""
)

const (
    driverNameMysql = "mysql"

    helpInfo = `Usage of mysqldataexport:
  -port int
        the port for mysql,default:32085
  -addr string
        the address for mysql,default:10.146.145.67
  -user string
        the username for login mysql,default:dbuser

  -pwd  string
        the password for login mysql by the username,default:Admin@123
  -db   string
        the port for me to listen on,default:auditlogdb
  -tables string
        the tables will export data, multi tables separator by comma, default:op_log,sc_log,sys_log
    `
)

func init() {

    port := flag.Int("port", 32085, "the port for mysql,default:32085")
    addr := flag.String("addr", "10.146.145.67", "the address for mysql,default:10.146.145.67")
    user := flag.String("user", "dbuser", "the username for login mysql,default:dbuser")
    pwd := flag.String("pwd", "Admin@123", "the password for login mysql by the username,default:Admin@123")
    db := flag.String("db", "auditlogdb", "the port for me to listen on,default:auditlogdb")
    tabs := flag.String("tables", "op_log,sc_log,sys_log", "the tables will export data, multi tables separator by comma, default:op_log,sc_log,sys_log")

    flag.Usage = usage

    flag.Parse()

    tables = append(tables, strings.Split(*tabs, ",")...)

    dataSourceName = fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?charset=utf8", *user, *pwd, *addr, *port, *db)
}

func main() {

    count := len(tables)
    ch := make(chan bool, count)

    db, err := sql.Open(driverNameMysql, dataSourceName)
    defer db.Close()
    if err != nil {
        panic(err.Error())
    }

    // Open doesn't open a connection. Validate DSN data:
    err = db.Ping()
    if err != nil {
        panic(err.Error())
    }

    for _, table := range tables {
        go querySQL(db, table, ch)
    }

    for i := 0; i < count; i++ {
        <-ch
    }
    fmt.Println("Done!")
}

func querySQL(db *sql.DB, table string, ch chan bool) {
    fmt.Println("开始处理：", table)
    rows, err := db.Query(fmt.Sprintf("SELECT * from %s", table))

    if err != nil {
        panic(err)
    }

    columns, err := rows.Columns()
    if err != nil {
        panic(err.Error())
    }

    //values：一行的所有值,把每一行的各个字段放到values中，values长度==列数
    values := make([]sql.RawBytes, len(columns))
    // print(len(values))

    scanArgs := make([]interface{}, len(values))
    for i := range values {
        scanArgs[i] = &values[i]
    }

    //存所有行的内容totalValues
    totalValues := make([][]string, 0)
    for rows.Next() {

        //存每一行的内容
        var s []string

        //把每行的内容添加到scanArgs，也添加到了values
        err = rows.Scan(scanArgs...)
        if err != nil {
            panic(err.Error())
        }

        for _, v := range values {
            s = append(s, string(v))
            // print(len(s))
        }
        totalValues = append(totalValues, s)
    }

    if err = rows.Err(); err != nil {
        panic(err.Error())
    }
    writeToCSV(table+".csv", columns, totalValues)
    ch <- true
}

//writeToCSV
func writeToCSV(file string, columns []string, totalValues [][]string) {
    f, err := os.Create(file)
    // fmt.Println(columns)
    defer f.Close()
    if err != nil {
        panic(err)
    }
    //f.WriteString("\xEF\xBB\xBF")
    w := csv.NewWriter(f)
    for i, row := range totalValues {
        //第一次写列名+第一行数据
        if i == 0 {
            w.Write(columns)
            w.Write(row)
        } else {
            w.Write(row)
        }
    }
    w.Flush()
    fmt.Println("处理完毕：", file)
}

func usage() {
    fmt.Fprint(os.Stderr, helpInfo)
    flag.PrintDefaults()
}