2011-11-27 22 views
14

在我通過問題進行描述之前,我想指出我知道其他線程提出這個問題,但是沒有人能夠解決我的問題。只允許Android SQLite的唯一數據輸入?

我一直在使用BumpAPI來處理共享應用程序,它在接收到塊後將其保存到SQLite數據庫以便在列表視圖活動中進行檢索,但這一切都工作正常且數據已保存,但如果相同的文本被髮送兩次,它會被一次又一次地保存,列表視圖會顯示出來,從我讀過的內容中我需要'UNIQUE'標識符?但是對於SQL來說是全新的我對實現這一點感到茫然,這裏是我用來創建和添加條目的DataHelper類,是否有人會修改它或告訴我一個可能的解決方案?

非常感謝

public class DataHelper { 

    private static final String DATABASE_NAME = "tags.db"; 
    private static final int DATABASE_VERSION = 1; 
    private static final String TABLE_NAME = "TagTable"; 

    private Context context; 
    private SQLiteDatabase db; 

    private SQLiteStatement insertStmt; 
    private static final String INSERT = "insert into " 
     + TABLE_NAME + "(name) values (?)"; 

    public DataHelper(Context context) { 
     this.context = context; 
     OpenHelper openHelper = new OpenHelper(this.context); 
     this.db = openHelper.getWritableDatabase(); 
     this.insertStmt = this.db.compileStatement(INSERT); 
    } 

    public long insert(String name) { 
     this.insertStmt.bindString(1, name); 
     return this.insertStmt.executeInsert(); 

    } 



    public void deleteAll() { 
     this.db.delete(TABLE_NAME, null, null); 
    } 

    public List<String> selectAll() { 
     List<String> list = new ArrayList<String>(); 
     Cursor cursor = this.db.query(TABLE_NAME, new String[] { "name" }, 
     null, null, null, null, "name desc"); 
     if (cursor.moveToFirst()) { 
     do { 
      list.add(cursor.getString(0)); 
     } while (cursor.moveToNext()); 
     } 
     if (cursor != null && !cursor.isClosed()) { 
     cursor.close(); 
     } 
     return list; 
    } 

    private static class OpenHelper extends SQLiteOpenHelper { 

     OpenHelper(Context context) { 
     super(context, DATABASE_NAME, null, DATABASE_VERSION); 
     } 

     @Override 
     public void onCreate(SQLiteDatabase db) { 
     db.execSQL("CREATE TABLE " + TABLE_NAME + "(id INTEGER PRIMARY KEY, name TEXT)" + "text unique, " + "ON CONFLICT REPLACE"); 
     } 

     @Override 
     public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
     db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME); 
     onCreate(db); 
     } 
    } 
} 

回答

38

unique關鍵字添加到列。

db.execSQL("CREATE TABLE " + TABLE_NAME + "(id INTEGER PRIMARY KEY, name TEXT unique); 
0

看起來你應該先添加表唯一索引創建語句

db.execSQL("CREATE TABLE " + TABLE_NAME + "(id INTEGER PRIMARY KEY, name TEXT)" + "**name** unique, " + "ON CONFLICT REPLACE"); 

它會阻止從具有相同名稱

第二兩個條目您可以選擇在實際插入之前檢查數據是否存在

+0

似乎也沒有工作,如果我查看SQL數據庫有重複條目的再次HM – Broak

+0

整理出來自己到底!恥辱noone甚至試圖幫助解答,但嘿,繼承人解決方案,如果有人需要它: db.execSQL(「CREATE TABLE」+ TABLE_NAME +「(id INTEGER PRIMARY KEY,name TEXT unique); – Broak