I want to change the sqlite database .db file to excel.
但我无法找到我到底要做什么。任何人都可以用一种简单的方式详细说明我必须执行的任务才能完成这项任务。
通过在Google上搜索，会出现如此多的链接，但我无法逐步理解这一点。
我已关注以下链接：
1。 How to convert excel sheet into database of sqlite in android
2。 SQlite database programmatically convert into Excel file format in Android
答案 0 :(得分：9)
我的解决方案是在第一步将sqlite数据库转换为csv然后在第二步将csv文件转换为xls并且它对我来说工作正常，你将需要2个库（opencsv-1.7.jar; poi-3.8 -20120326.jar）
public class ExportDatabaseCSVTask extends AsyncTask<String, Void, Boolean>
{
private final ProgressDialog dialog = new ProgressDialog(DatabaseExampleActivity.this);
@Override
protected void onPreExecute()
{
this.dialog.setMessage("Exporting database...");
this.dialog.show();
}
protected Boolean doInBackground(final String... args)
{
File dbFile=getDatabasePath("database_name");
//AABDatabaseManager dbhelper = new AABDatabaseManager(getApplicationContext());
AABDatabaseManager dbhelper = new AABDatabaseManager(DatabaseExampleActivity.this) ;
System.out.println(dbFile); // displays the data base path in your logcat
File exportDir = new File(Environment.getExternalStorageDirectory(), "");
if (!exportDir.exists())
{
exportDir.mkdirs();
}
File file = new File(exportDir, "excerDB.csv");
try
{
if (file.createNewFile()){
System.out.println("File is created!");
System.out.println("myfile.csv "+file.getAbsolutePath());
}else{
System.out.println("File already exists.");
}
CSVWriter csvWrite = new CSVWriter(new FileWriter(file));
//SQLiteDatabase db = dbhelper.getWritableDatabase();
Cursor curCSV=db.getdb().rawQuery("select * from " + db.TABLE_NAME,null);
csvWrite.writeNext(curCSV.getColumnNames());
while(curCSV.moveToNext())
{
String arrStr[] ={curCSV.getString(0),curCSV.getString(1),curCSV.getString(2)};
/*curCSV.getString(3),curCSV.getString(4)};*/
csvWrite.writeNext(arrStr);
}
csvWrite.close();
curCSV.close();
/*String data="";
data=readSavedData();
data= data.replace(",", ";");
writeData(data);*/
return true;
}
catch(SQLException sqlEx)
{
Log.e("MainActivity", sqlEx.getMessage(), sqlEx);
return false;
}
catch (IOException e)
{
Log.e("MainActivity", e.getMessage(), e);
return false;
}
}
protected void onPostExecute(final Boolean success)
{
if (this.dialog.isShowing())
{
this.dialog.dismiss();
}
if (success)
{
Toast.makeText(DatabaseExampleActivity.this, "Export succeed", Toast.LENGTH_SHORT).show();
}
else
{
Toast.makeText(DatabaseExampleActivity.this, "Export failed", Toast.LENGTH_SHORT).show();
}
}}
将CSV导出到XLS部分
public class CSVToExcelConverter extends AsyncTask<String, Void, Boolean> {
private final ProgressDialog dialog = new ProgressDialog(DatabaseExampleActivity.this);
@Override
protected void onPreExecute()
{this.dialog.setMessage("Exporting to excel...");
this.dialog.show();}
@Override
protected Boolean doInBackground(String... params) {
ArrayList arList=null;
ArrayList al=null;
//File dbFile= new File(getDatabasePath("database_name").toString());
File dbFile=getDatabasePath("database_name");
String yes= dbFile.getAbsolutePath();
String inFilePath = Environment.getExternalStorageDirectory().toString()+"/excerDB.csv";
outFilePath = Environment.getExternalStorageDirectory().toString()+"/test.xls";
String thisLine;
int count=0;
try {
FileInputStream fis = new FileInputStream(inFilePath);
DataInputStream myInput = new DataInputStream(fis);
int i=0;
arList = new ArrayList();
while ((thisLine = myInput.readLine()) != null)
{
al = new ArrayList();
String strar[] = thisLine.split(",");
for(int j=0;j<strar.length;j++)
{
al.add(strar[j]);
}
arList.add(al);
System.out.println();
i++;
}} catch (Exception e) {
System.out.println("shit");
}
try
{
HSSFWorkbook hwb = new HSSFWorkbook();
HSSFSheet sheet = hwb.createSheet("new sheet");
for(int k=0;k<arList.size();k++)
{
ArrayList ardata = (ArrayList)arList.get(k);
HSSFRow row = sheet.createRow((short) 0+k);
for(int p=0;p<ardata.size();p++)
{
HSSFCell cell = row.createCell((short) p);
String data = ardata.get(p).toString();
if(data.startsWith("=")){
cell.setCellType(Cell.CELL_TYPE_STRING);
data=data.replaceAll("\"", "");
data=data.replaceAll("=", "");
cell.setCellValue(data);
}else if(data.startsWith("\"")){
data=data.replaceAll("\"", "");
cell.setCellType(Cell.CELL_TYPE_STRING);
cell.setCellValue(data);
}else{
data=data.replaceAll("\"", "");
cell.setCellType(Cell.CELL_TYPE_NUMERIC);
cell.setCellValue(data);
}
//*/
// cell.setCellValue(ardata.get(p).toString());
}
System.out.println();
}
FileOutputStream fileOut = new FileOutputStream(outFilePath);
hwb.write(fileOut);
fileOut.close();
System.out.println("Your excel file has been generated");
} catch ( Exception ex ) {
ex.printStackTrace();
} //main method ends
return true;
}
protected void onPostExecute(final Boolean success)
{
if (this.dialog.isShowing())
{
this.dialog.dismiss();
}
if (success)
{
Toast.makeText(DatabaseExampleActivity.this, "file is built!", Toast.LENGTH_LONG).show();
}
else
{
Toast.makeText(DatabaseExampleActivity.this, "file fail to build", Toast.LENGTH_SHORT).show();
}
}
}
答案 1 :(得分：4)
我知道这个问题有点旧，但它为我提供了同一个问题的答案。我已经清理了一些代码，并且通过让我的数据库帮助器类返回一个ArrayList来完全编写一个csv文件。仍然使用Apache POI。
File folder =new File(Environment.getExternalStorageDirectory()+APP_FILES_PATH);
if(!folder.exists())
{
folder.mkdir();
}
DatabaseHelper dbHelper = DatabaseHelper.getInstance(context);
ArrayList<String[]> exts = dbHelper.getExtinguisherArray(1);
HSSFWorkbook hwb = new HSSFWorkbook();
HSSFSheet sheet = hwb.createSheet("extinguishers");
for(int x = 0; x < exts.size(); x++)
{
String[] arr = exts.get(x);
HSSFRow row = sheet.createRow(x);
for(int i = 0; i< arr.length; i++)
{
HSSFCell cell = row.createCell(i);
String data = arr[i];
cell.setCellValue(data);
}
}
FileOutputStream fileOut = new FileOutputStream(Environment.getExternalStorageDirectory()+APP_FILES_PATH+"file.xls");
hwb.write(fileOut);
fileOut.close();
答案 2 :(得分：2)
添加此jar文件 opencsv-1.7.jar http://www.java2s.com/Code/Jar/o/Downloadopencsv17jar.htm
然后使用此代码
public class ExportDatabaseToCSV{
Context context;
public ExportDatabaseToCSV(Context context) {
this.context=context;
}
public void exportDataBaseIntoCSV(){
CredentialDb db = new CredentialDb(context);//here CredentialDb is my database. you can create your db object.
File exportDir = new File(Environment.getExternalStorageDirectory(), "");
if (!exportDir.exists())
{
exportDir.mkdirs();
}
File file = new File(exportDir, "csvfilename.csv");
try
{
file.createNewFile();
CSVWriter csvWrite = new CSVWriter(new FileWriter(file));
SQLiteDatabase sql_db = db.getReadableDatabase();//here create a method ,and return SQLiteDatabaseObject.getReadableDatabase();
Cursor curCSV = sql_db.rawQuery("SELECT * FROM "+CredentialDb.TABLE_NAME,null);
csvWrite.writeNext(curCSV.getColumnNames());
while(curCSV.moveToNext())
{
//Which column you want to export you can add over here...
String arrStr[] ={curCSV.getString(0),curCSV.getString(1), curCSV.getString(2)};
csvWrite.writeNext(arrStr);
}
csvWrite.close();
curCSV.close();
}
catch(Exception sqlEx)
{
Log.e("Error:", sqlEx.getMessage(), sqlEx);
}
}
}
答案 3 :(得分：1)
除了@ user2324120的回答，以及我们在Android中，您可以直接将库添加到gradle（因此您不需要下载jar）：
compile 'com.opencsv:opencsv:3.7'
compile 'org.apache.poi:poi:3.14'
我也采用了不同的方式，一种更可定制的方式（没有无用的CSV转换）。这里有一些评论：
public static Pair<Boolean, String> exportToXLS(Context context, boolean byAuthor) {
try {
HSSFWorkbook workbook = new HSSFWorkbook();
HSSFSheet sheet = workbook.createSheet(context.getString(R.string.sheet_name)); // Good for localization
initSheetColumns(context, workbook, sheet, byAuthor);
addBooksToSheet(sheet, byAuthor);
setColumsWidth(sheet);
OutputStream outputStream = new FileOutputStream(new File(Methods.getDownloadsDirectory(), byAuthor ? context.getString(R.string.mylibrary_by_author_xls) : context.getString(R.string.mylibrary_xls)).getAbsolutePath());
workbook.write(outputStream);
outputStream.flush();
outputStream.close();
return new Pair<>(true, context.getString(R.string.database_saved));
} catch (Exception e) {
e.printStackTrace();
return new Pair<>(false, context.getString(R.string.an_error_has_occured_during_xls_file_creation));
}
}
private static void initSheetColumns(Context context, HSSFWorkbook workbook, HSSFSheet sheet, boolean byAuthor) {
HSSFRow row = sheet.createRow(0);
HSSFCell cell = row.createCell(0);
cell.setCellValue(byAuthor ? context.getString(R.string.db_author) : context.getString(R.string.db_title));
cell = row.createCell(1);
cell.setCellValue(byAuthor ? context.getString(R.string.db_title) : context.getString(R.string.db_author));
cell = row.createCell(2);
cell.setCellValue(context.getString(R.string.db_publisheddate));
/*
etc.
*/
boldHeaders(workbook, row);
}
private static void boldHeaders(HSSFWorkbook workbook, HSSFRow row) {
HSSFCellStyle style = workbook.createCellStyle();
/* Do your own style
...
*/
for (int i = 0; i < 8; i++) {
row.getCell(i).setCellStyle(style);
}
}
// Allow data personalisation and localisation if needed
private static void addBooksToSheet(HSSFSheet sheet, boolean byAuthor) {
int i = 1;
List<Book> books = Book.listAll(Book.class); // I use Sugar library here, if you're not just make a simple db query to get your objects
Collections.sort(books, byAuthor ? Book.bookAuthorComparator : Book.bookNameComparator);
for (Book book : books) {
HSSFRow row = sheet.createRow(i);
HSSFCell cell = row.createCell(0);
cell.setCellValue(byAuthor ? getBookValue(book, true) : book.getTitle());
cell = row.createCell(1);
cell.setCellValue(byAuthor ? book.getTitle() : getBookValue(book, false));
cell = row.createCell(2);
cell.setCellValue(book.getPublishedDate());
/*
etc.
*/
i++;
}
}
private static void setColumsWidth(HSSFSheet sheet) {
for (int i = 0; i < 8; i++) {
sheet.setColumnWidth(i, 255 * getMaxNumCharacters(sheet, i)); // Autosize not working on Android
}
}
// My method to get the max num char, if it can hekp
public static int getMaxNumCharacters(Sheet sheet, int column) {
int max = 0;
for (int rowIndex = 0; rowIndex <= sheet.getLastRowNum(); rowIndex++) {
Row row = sheet.getRow(rowIndex);
if (row == null) {
continue;
}
Cell cell = row.getCell(column);
if (cell != null) {
int nb = cell.getStringCellValue().length();
if (nb > max) {
max = nb;
}
}
}
max = (int) (max * 1.1);
if (max > 255) {
return 255; // max 255 char for width
}
return max;
}
希望它有所帮助！