ANDROID SQLITE检查，如果表中有数据 [英] ANDROID SQLITE check if table has data

问题描述

我想检查我的表中有记录。以下是我已经试过：

I'd like to check if my table has records. Here's what I've tried:

if( cursor != null ){
        cursor.moveToFirst();
        if (cursor.getInt(0) == 0) {
        Toast.makeText(getBaseContext(), "No records yet!", Toast.LENGTH_SHORT).show();
        }
    }

LogCat中说：

Logcat says:

  CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0

任何帮助是AP preciated。谢谢。

Any help is appreciated. Thanks.

推荐答案

试试这个

cursor.getCount();

如果游标检索如果给0数据指望它会返回那么就没有数据

it will return if cursor retrieve data count if this give 0 then there is no data

所以

if(cursor != null && cursor.getCount()>0){
   cursor.moveToFirst();
   //do your action
   //Fetch your data

}
else {
 Toast.makeText(getBaseContext(), "No records yet!", Toast.LENGTH_SHORT).show();
    return;
}  

请注意：即使你检查如果（指针！= NULL）光标做任何的查询后，将不会返回空值，所以做这个检查在光标的数据计数之后

Note : even though you check if( cursor != null ) cursor will not return null value after doing any query, so do this to check the data count in cursor after that

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