private fun exportCSV(){
        val exportDir = File(getExternalStorageDirectory(), "/CSV")// your path where you want save your file
        if (!exportDir.exists()) {
            exportDir.mkdirs()
        }

        val file = File(exportDir, "$TABLE_NAME.csv")//$TABLE_NAME.csv is like user.csv or any name you want to save
        try {
            file.createNewFile()
            val csvWrite = CSVWriter(FileWriter(file))
            val curCSV = database.query("SELECT * FROM $TABLE_NAME", null)// query for get all data of your database table
            csvWrite.writeNext(curCSV.columnNames)
            while (curCSV.moveToNext()) {
                //Which column you want to export
                val arrStr = arrayOfNulls<String>(curCSV.columnCount)
                for (i in 0 until curCSV.columnCount - 1) {
                    when (i) {
                        20, 22 -> {
                        }
                        else -> arrStr[i] = curCSV.getString(i)
                    }
                }
                csvWrite.writeNext(arrStr)
            }
            csvWrite.close()
            curCSV.close()
            showToast("Exported SuccessFully",this)
        } catch (sqlEx: Exception) {
            Timber.e(sqlEx)
        }

    } 

private fun importCSV(){
       val csvReader =
           CSVReader(FileReader("${getExternalStorageDirectory()}/CSV/$TABLE_NAME.csv"))/* path of local storage (it should be your csv file locatioin)*/
       var nextLine: Array<String> ? = null
       var count = 0
       val columns = StringBuilder()
       GlobalScope.launch(Dispatchers.IO) {
           do {
               val value = StringBuilder()
               nextLine = csvReader.readNext()
               nextLine?.let {nextLine->
                   for (i in 0 until nextLine.size - 1) {
                       if (count == 0) {                             // the count==0 part only read
                           if (i == nextLine.size - 2) {             //your csv file column name
                               columns.append(nextLine[i])          
                               count =1             
                           }
                           else
                               columns.append(nextLine[i]).append(",")
                       } else {                         // this part is for reading value of each row
                           if (i == nextLine.size - 2) {
                               value.append("'").append(nextLine[i]).append("'")
                               count = 2
                           }
                           else
                               value.append("'").append(nextLine[i]).append("',")
                       }
                   }
                   if (count==2) {
                       customerViewModel.pushCustomerData(columns, value)//write here your code to insert all values
                   }
               }
           }while ((nextLine)!=null)
       }

       showToast("Imported SuccessFully",this)
   }

   fun insertDataRawFormat(query: SupportSQLiteQuery): Boolean? 

suspend fun pushCustomerData(columns:StringBuilder,values:StringBuilder) = withContext(Dispatchers.IO){
        val query = SimpleSQLiteQuery(
            "INSERT INTO customer ($columns) values($values)",
            arrayOf()
        )
        customerDao.insertDataRawFormat(query)
    }