Question

以下是我的表格：

db.execSQL("CREATE TABLE "+ callTable+" ("+ colID + " INTEGER PRIMARY KEY AUTOINCREMENT, "+ colPhNum + " TEXT, " + colDur + " INTEGER, "
           + colDate + " INTEGER, " + colDay + " TEXT, " + colYear + " INTEGER, " + colType + " TEXT, " + colStTime + " TEXT, " + colHour + " INTEGER, " + colMonth +  " INTEGER)");

我试图执行此查询：

SQLiteDatabase db=this.getWritableDatabase();

String j = "SELECT " + colPhNum + "," + "SUM(" +colDur +") FROM " + callTable +" WHERE " + colYear + "=" + y+ " AND " +colMonth +"=" + m + " AND " +colDate + "=" + d + " AND " + colHour + ">" + h
         + " GROUP BY " + colPhNum;

Cursor c = db.rawQuery(j,null);
c.close();
return c;

但这不起作用。这是错误日志：

D/AndroidRuntime(  209): Shutting down VM
W/dalvikvm(  209): threadid=3: thread exiting with uncaught exception (group=0x4001b188)
E/AndroidRuntime(  209): Uncaught handler: thread main exiting due to uncaught exception
E/AndroidRuntime(  209): java.lang.IllegalStateException: attempt to acquire a reference on a close SQLiteClosable
E/AndroidRuntime(  209):    at android.database.sqlite.SQLiteClosable.acquireReference(SQLiteClosable.java:31)
E/AndroidRuntime(  209):    at android.database.sqlite.SQLiteQuery.fillWindow(SQLiteQuery.java:69)
E/AndroidRuntime(  209):    at  android.database.sqlite.SQLiteCursor.fillWindow(SQLiteCursor.java:288)
E/AndroidRuntime(  209):    at android.database.sqlite.SQLiteCursor.getCount(SQLiteCursor.java:269)

请帮忙。

Answer 1

在查询之前添加以下代码并尝试

db = openOrCreateDatabase（ “databasename.db” ，SQLiteDatabase.CREATE_IF_NECESSARY ，空值）;

数据库查询不起作用

1 个答案: