SQLITE3查询未在Android

Question

正常运行，我有这样的

SELECT value1 FROM mytable where (value1 > value2) AND category = 1 ; 

此查询不能在Android的正确执行。虽然如果我手动去

/data/data/packagename/databases/mydatabase.db 

这里是代码

try { 
SQLiteDatabase sqdb = _context.openOrCreateDatabase(_DB_NAME, 0, 
       null); 
String sql = null; 
sql = "SELECT value1 FROM mytable where (value1 > value2) AND category = " + category 
       +"; "; 
Cursor c = sqdb.rawQuery(sql, null); 
Log.i("sql = ", sql); 

if (c.moveToFirst()) { 
while (!c.isAfterLast()) { 

categoryValue = c.getString(0); 
c.moveToNext(); 
} 
} 
Log.i("categoryValue", categoryValue); 
sqdb.close(); 
c.close(); 
} catch (Exception e) { 
e.printStackTrace(); 
} 

然后执行它。然后它完美地工作。

发生了什么事？

Answer 1

我认为首先你需要关闭光标然后数据库连接

//the order should be 
c.close(); 
sqdb.close();