Question

我的DatabaseHandler类：

public class DatabaseHandler extends SQLiteOpenHelper {

    private static final String LOG_TAG = "debugger";

    //database version
    private static final int DATABASE_VERSION = 1;
    //database name;
    private static final String DATABASE_NAME = "appdb";

    private static final String TABLE_PROJECT = "projects";     
    //Project Table Columns
    private static String PROJECT_ID = "Project_id";
    private static final String PROJECT_NAME = "Name";
    private static final String PROJECT_DESCRIPTION = "Description";
    private static final String CLIENT_NAME = "Client_Name";
    private static final String LOCATION = "Location";

    public DatabaseHandler(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);

    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        Log.d(LOG_TAG, "Executing OnCreate");   
        createProjectTable(db);     
    }

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

    }

    private void createProjectTable(SQLiteDatabase db){
        String CREATE_PROJECT_TABLE = "CREATE TABLE " + TABLE_PROJECT + "("
        + PROJECT_ID + " INTEGER PRIMARY KEY, "
        + PROJECT_NAME + " TEXT, "
        + PROJECT_DESCRIPTION + " TEXT, "
        + CLIENT_NAME + " TEXT, "
        + LOCATION + " TEXT );";
        Log.d(LOG_TAG, "Creating Project table --> " + CREATE_PROJECT_TABLE);
        db.execSQL(CREATE_PROJECT_TABLE);
    }   

    public void addProject(Project project){
         SQLiteDatabase db = this.getWritableDatabase();
         ContentValues values = new ContentValues();
         values.put(PROJECT_NAME, project.getName()); // Contact Name
         values.put(PROJECT_DESCRIPTION, project.getDescription()); // Contact Phone
         values.put(CLIENT_NAME, project.getClient_name());
         values.put(LOCATION, project.getLocation());
         // Inserting Row
         Log.d(LOG_TAG, "Inserting Project....");
         db.insert(TABLE_PROJECT, null, values);
         Log.d(LOG_TAG, "Inserted successfullyt....");
         db.close(); // Closing database connection
    }

    public List<Project> getProjects(){
        List<Project> projects = new ArrayList<Project>();
        String selectQuery = "SELECT  * FROM " + TABLE_PROJECT;
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.rawQuery(selectQuery, null);
        if(cursor.getCount() != 0){
            Log.d(LOG_TAG, "Projects found...");
          if (cursor.moveToFirst()) {
            do {
                Project project = new Project();
                project.setName(cursor.getString(1));
                project.setClient_name(cursor.getString(2));
                project.setDescription(cursor.getString(3));
                project.setLocation(cursor.getString(4));
                projects.add(project);
            } while (cursor.moveToNext());
          }
        }
      return projects;
    }

    public void updateProject(Project project){
         SQLiteDatabase db = this.getWritableDatabase();
         ContentValues values = new ContentValues();
         values.put(PROJECT_NAME, project.getName()); // Contact Name
         values.put(PROJECT_DESCRIPTION, project.getDescription()); // Contact Phone
         values.put(CLIENT_NAME, project.getClient_name());
         values.put(LOCATION, project.getLocation());
         String where = PROJECT_ID + " = ? ";       
         String [] value = { String.valueOf(project.getProject_id()) };
         try{
             int count = db.update(TABLE_PROJECT, values, where , value);
             Log.d(LOG_TAG, "Updated rows -> " + count);
         }catch (Exception e) {
            e.printStackTrace();
        }
        db.close();
    }
}

在我的活动中

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(...);
dbHelper = new DatabaseHandler(this);
}

当用户点击更新按钮时，我会调用更新方法

dbHelper.updateProject(newProject);

在updateProject中的dbHelper方法中，count的值为0。

即使在update方法之后调用此方法，dbHelper.getProjects()也会返回旧值。

我已经使用调试器检查了新值是否传递给updateProject方法，但它们没有得到反映。方法addProject运行正常。

Project class

public class Project implements Serializable{

    private static final long serialVersionUID = 1L;
    private int project_id;
    private String name;
    private String description;
    private String client_name;
    private String location;

    public Project(){

    }

    public Project(int project_id, String name, String client_name,String description, String location){
        this.project_id = project_id;
        this.name = name;
        this.description = description;
        this.client_name = client_name;
        this.location = location;
    }

    public int getProject_id() {
        return project_id;
    }

    public void setProject_id(int project_id) {
        this.project_id = project_id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public String getClient_name() {
        return client_name;
    }

    public void setClient_name(String client_name) {
        this.client_name = client_name;
    }

    public String getLocation() {
        return location;
    }

    public void setLocation(String location) {
        this.location = location;
    }

}

任何人都可以帮忙。

Answer 1

试试这个......

 String [] value = { Integer.toString(project.getProject_id()) };

Answer 2

使用此 -

String[] value = new String []{ String.valueOf(project.getProject_id()) };

Answer 3

项目标识属于int数据类型，因此您应该使用

  int value = project.getProject_id();

Android SQlite没有更新数据

3 个答案: