hotime/db/backup.go

package db

import (
	. "code.hoteas.com/golang/hotime/common"
	"os"
	"strings"
)

// backupSave 保存备份
// path: 备份文件路径
// tt: 表名
// code: 备份类型 0=全部, 1=仅数据, 2=仅DDL
func (that *HoTimeDB) backupSave(path string, tt string, code int) {
	fd, _ := os.OpenFile(path, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0644)
	defer fd.Close()

	q := "`"
	if that.Dialect != nil {
		q = that.Dialect.QuoteChar()
	}

	str := "\r\n"
	if code == 0 || code == 2 {
		str += that.backupDdl(tt)
	}

	if code == 0 || code == 1 {
		str += "insert  into " + q + tt + q + "\r\n\r\n("
		str += that.backupCol(tt)
	}

	_, _ = fd.Write([]byte(str))
}

// backupDdl 备份表结构（DDL）
func (that *HoTimeDB) backupDdl(tt string) string {
	switch that.Type {
	case "dm", "dameng":
		return that.backupDdlDM(tt)
	default:
		data := that.Query("show create table " + tt)
		if len(data) == 0 {
			return ""
		}
		return ObjToStr(data[0]["Create Table"]) + ";\r\n\r\n"
	}
}

// backupDdlDM 达梦数据库 DDL 导出
func (that *HoTimeDB) backupDdlDM(tt string) string {
	cols := that.Query(`SELECT COLUMN_NAME, DATA_TYPE, DATA_LENGTH, DATA_PRECISION, DATA_SCALE, NULLABLE, DATA_DEFAULT FROM USER_TAB_COLUMNS WHERE TABLE_NAME='` + tt + `' ORDER BY COLUMN_ID`)
	if len(cols) == 0 {
		return ""
	}

	ddl := "CREATE TABLE \"" + tt + "\" (\r\n"
	for i, col := range cols {
		name := col.GetString("COLUMN_NAME")
		dtype := col.GetString("DATA_TYPE")
		nullable := col.GetString("NULLABLE")
		defVal := col.GetString("DATA_DEFAULT")

		colDef := "  \"" + name + "\" " + dtype
		prec := col.GetInt("DATA_PRECISION")
		scale := col.GetInt("DATA_SCALE")
		length := col.GetInt("DATA_LENGTH")
		if prec > 0 {
			colDef += "(" + ObjToStr(prec)
			if scale > 0 {
				colDef += "," + ObjToStr(scale)
			}
			colDef += ")"
		} else if length > 0 && (strings.Contains(strings.ToUpper(dtype), "CHAR") || strings.Contains(strings.ToUpper(dtype), "BINARY")) {
			colDef += "(" + ObjToStr(length) + ")"
		}

		if nullable == "N" {
			colDef += " NOT NULL"
		}
		if defVal != "" {
			colDef += " DEFAULT " + strings.TrimSpace(defVal)
		}

		if i < len(cols)-1 {
			colDef += ","
		}
		ddl += colDef + "\r\n"
	}
	ddl += ");\r\n\r\n"
	return ddl
}

// backupCol 备份表数据
func (that *HoTimeDB) backupCol(tt string) string {
	q := "`"
	if that.Dialect != nil {
		q = that.Dialect.QuoteChar()
	}

	str := ""
	data := that.Select(tt, "*")

	lthData := len(data)

	if lthData == 0 {
		return str
	}

	lthCol := len(data[0])
	col := make([]string, lthCol)
	tempLthData := 0

	for k := range data[0] {
		if tempLthData == lthCol-1 {
			str += q + k + q + ") "
		} else {
			str += q + k + q + ","
		}
		col[tempLthData] = k
		tempLthData++
	}

	str += " values"

	for j := 0; j < lthData; j++ {
		for m := 0; m < lthCol; m++ {
			if m == 0 {
				str += "("
			}

			v := "NULL"
			if data[j][col[m]] != nil {
				v = "'" + strings.Replace(ObjToStr(data[j][col[m]]), "'", `\'`, -1) + "'"
			}

			if m == lthCol-1 {
				str += v + ") "
			} else {
				str += v + ","
			}
		}

		if j == lthData-1 {
			str += ";\r\n\r\n"
		} else {
			str += ",\r\n\r\n"
		}
	}

	return str
}