Java 向SQLITE数据库添加数据

我在资产中有一个SQLite DB文件，然后导入到应用程序中。 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，它将不起作用。我没有错误，因此我可以确定问题

DatabaseHelper类：addProject（）方法用于插入数据

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();
                }
    }
        });

---

我想您在执行insert操作之前忘记打开数据库了

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();
            }
        }
    });

---

不管怎么说，这似乎是个问题，看看吧

我正在从资产文件导入数据库您收到toast了吗？是的，我收到一个toast，上面写着“添加成功”，但如果我打开数据库，它不会添加数据。我尝试添加上面的行，但没有帮助。我还尝试了

myDatabase.openDatabase（）@VishalKinjavdekar在DbHelperClass中创建名为
open（）
的新方法，并在此方法中写入
myDatabase.open（）
，然后在插入之前调用它