Question

我在资产中有一个SQLite DB文件，然后在应用程序中导入。 select查询工作正常并显示结果但同时如果我尝试将数据插入表中则不起作用。我没有收到任何错误，以便我能够确定问题。

DatabaseHelper类： addProject（）方法是插入数据。

public class DatabaseHelper extends SQLiteOpenHelper {
    private static final int DB_VERSION=1;
    private static String DB_PATH="";
    private static final String DB_NAME="AndroidProject.sqlite";

    //Projects Table attrib
    String TABLE_PROJECT="Project";
    String KEY_PROJECT_ID = "_id";
    String KEY_PROJECT_NAME = "project_name";
    String KEY_PROJECT_DESC = "project_desc";
    String KEY_PROJECT_TYPE = "project_type";
    String KEY_PROJECT_START_DATE = "start_date";
    String KEY_PROJECT_END_DATE = "end_date";

    private SQLiteDatabase myDatabase;
    private final Context myContext;

    public DatabaseHelper(Context context) {
        super(context, DB_NAME, null, DB_VERSION);

        if (Build.VERSION.SDK_INT>=15){
            DB_PATH=context.getApplicationInfo().dataDir + "/databases/";
        }
        else {
            DB_PATH= Environment.getDataDirectory() + "/data/" + context.getPackageName() + "/databases/";
        }
        this.myContext = context;
    }


    @Override
    public void onCreate(SQLiteDatabase db) {

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    }

    public void  checkAndCopyDatabase(){
        boolean doExists=checkDatabase();
        if (doExists){
            Log.d("TAG", "Database alredy exists");
        }
        else{
            this.getReadableDatabase();
        }
        try {
            copyDatabase();
        } catch (IOException e) {
            e.printStackTrace();
            Log.d("TAG", "Error Copying DATABASE");
        }
    }

    public boolean checkDatabase(){
        SQLiteDatabase checkDB=null;
        try {
            String myPath=DB_PATH+DB_NAME;
            checkDB=SQLiteDatabase.openDatabase(myPath,null,SQLiteDatabase.OPEN_READWRITE);
        }catch (SQLiteException e){

        }
        if (checkDB != null) {
            checkDB.close();
        }

        return checkDB != null ? true : false;
    }

    public void copyDatabase() throws IOException {
        InputStream myInput = myContext.getAssets().open(DB_NAME);
        String outFileName = DB_PATH + DB_NAME;
        OutputStream myOutput = new FileOutputStream(outFileName);
        byte[] buffer = new byte[1024];
        int length;

        while ((length=myInput.read(buffer))>0){
            myOutput.write(buffer,0,length);
        }
        myOutput.flush();
        myOutput.close();
        myInput.close();
    }

    public void openDatabase(){
        String myPath = DB_PATH + DB_NAME;
        myDatabase=SQLiteDatabase.openDatabase(myPath,null,SQLiteDatabase.OPEN_READWRITE);
    }

    public synchronized void close(){
        if (myDatabase != null){
            myDatabase.close();
        }

        super.close();
    }

    public Cursor QueryData(String query){
        return myDatabase.rawQuery(query,null);
    }


    public void addProject(SqlProjects blog){

            //SQLiteDatabase db = this.getWritableDatabase();
            ContentValues values = new ContentValues();
            values.put(KEY_PROJECT_NAME, blog.get_project_name());
            values.put(KEY_PROJECT_DESC, blog.get_project_desc());
            values.put(KEY_PROJECT_TYPE, blog.get_project_type());
            values.put(KEY_PROJECT_START_DATE, blog.get_project_start_date());
            values.put(KEY_PROJECT_END_DATE, blog.get_project_end_date());


            try {
                Log.d("TAG", "Adding data");
                myDatabase.insertOrThrow(TABLE_PROJECT, null, values);
            } catch (SQLiteException e) {

                e.printStackTrace();
            }




        myDatabase.close();
    }
}

SqlProjects类构造函数，getter和setter

public class SqlProjects {

    private DatabaseHelper helper;

    int _id;
    String _project_name, _project_desc,_project_type;
    String _project_start_date,_project_end_date;


    public SqlProjects() {
    }

    public SqlProjects(String _project_name, String _project_desc, String _project_type, String _project_start_date, String _project_end_date) {
        this._project_name = _project_name;
        this._project_desc = _project_desc;
        this._project_type = _project_type;
        this._project_start_date = _project_start_date;
        this._project_end_date = _project_end_date;
    }


    public SqlProjects(int _id, String _project_name, String _project_desc, String _project_type, String _project_start_date, String _project_end_date) {
        this._id = _id;
        this._project_name = _project_name;
        this._project_desc = _project_desc;
        this._project_type = _project_type;
        this._project_start_date = _project_start_date;
        this._project_end_date = _project_end_date;
    }

    public int get_project_id() {
        return _id;
    }

    public void set_project_id(int _project_id) {
        this._id = _project_id;
    }

    public String get_project_name() {
        return _project_name;
    }

    public void set_project_name(String _project_name) {
        this._project_name = _project_name;
    }

    public String get_project_desc() {
        return _project_desc;
    }

    public void set_project_desc(String _project_desc) {
        this._project_desc = _project_desc;
    }

    public String get_project_type() {
        return _project_type;
    }

    public void set_project_type(String _project_type) {
        this._project_type = _project_type;
    }

    public String get_project_start_date() {
        return _project_start_date;
    }

    public void set_project_start_date(String _project_start_date) {
        this._project_start_date = _project_start_date;
    }

    public String get_project_end_date() {
        return _project_end_date;
    }

    public void set_project_end_date(String _project_end_date) {
        this._project_end_date = _project_end_date;
    }
}

主要类

    final DatabaseHelper db = new DatabaseHelper(Add_Project.this);

btnAddProjects.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (!(TextUtils.isEmpty(editName.getText().toString())) && !(TextUtils.isEmpty(editDesc.getText().toString())) && !(tvStartDate.getText().equals("")) && !(tvEndDate.getText().equals(""))) {

                    db.addProject(new SqlProjects(editName.getText().toString(), editDesc.getText().toString(), editType.getSelectedItem().toString(), tvStartDate.getText().toString(), tvEndDate.getText().toString()));

                    editName.setText("");
                    editDesc.setText("");
                    tvStartDate.setText("");
                    tvEndDate.setText("");

                    Toast.makeText(getApplicationContext(), "Added Successfully", Toast.LENGTH_SHORT).show();
                    onBackPressed();
                }
    }
        });

Answer 1

我认为您在插入操作之前忘记打开数据库。

btnAddProjects.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if (!(TextUtils.isEmpty(editName.getText().toString())) && !(TextUtils.isEmpty(editDesc.getText().toString())) && !(tvStartDate.getText().equals("")) && !(tvEndDate.getText().equals(""))) {
                //open db before any operation
                db.openDatabase();
                db.addProject(new SqlProjects(editName.getText().toString(), editDesc.getText().toString(), editType.getSelectedItem().toString(), tvStartDate.getText().toString(), tvEndDate.getText().toString()));

                editName.setText("");
                editDesc.setText("");
                tvStartDate.setText("");
                tvEndDate.setText("");

                Toast.makeText(getApplicationContext(), "Added Successfully", Toast.LENGTH_SHORT).show();
                onBackPressed();
            }
        }
    });

似乎问题无论如何都要检查出来！

将数据添加到SQLiteDatabase

1 个答案: