SQLITE错误无法打开文件
[英]SQLITE error Unable to open file
问题描述
I want to create a database for an app in the data directory. 
我想在数据目录中为应用创建数据库。 I tried to use 我尝试使用
try{
String path = "/data/data/"+context+"/database/Einkaufsliste.sqlite";
database = SQLiteDatabase.openOrCreateDatabase(path,null);
}
But I get always the following exception: unable to open database file 但是我总是收到以下异常：无法打开数据库文件
Logcat gives the following result: Logcat给出以下结果：
04-10 19:55:09.387: E/SqliteDatabaseCpp(554): sqlite3_open_v2("/data/data/at.einkaufsliste/database/Einkaufsliste.sqlite", &handle, 6, NULL) failed 04-10 19:55:09.527: E/SQLiteDatabase(554): Failed to open the database.
I set the permission EXTERNAL Storage and the group permisson. 我设置了权限EXTERNAL Storage和组权限。
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<permission-group android:name="android.permission-group.STORAGE"></permission-group>
What is wrong with this usage? 这种用法有什么问题？
1 个解决方案
解决方案1
0 2014-04-10 20:10:37
What is wrong with this usage?
NEVER HARDCODE PATHS . 绝不困难的路径 。 /data/data is wrong for many users. /data/data对许多用户来说是错误的。 Use getDatabasePath() to get the location where a database file should go on internal storage. 使用getDatabasePath()获取数据库文件应在内部存储器上放置的位置。 This will also fix your problems with using string concatenation to build a path. 这也可以解决使用字符串连接构建路径的问题。
That would give you: 那会给你：
try {
database = SQLiteDatabase.openOrCreateDatabase(getDatabasePath("Einkaufsliste.sqlite"), null);
}
assuming that this code is called from a method in a subclass of Context . 假定此代码是从Context的子类中的方法调用的。 Otherwise, you will need to arrange to call getDatabasePath() on a Context . 否则，您将需要安排在Context上调用getDatabasePath() 。
I set the permission EXTERNAL Storage
If by this you mean that you have WRITE_EXTERNAL_STORAGE , that does not matter here, as you are not putting the database on external storage 如果您的意思是说您拥有WRITE_EXTERNAL_STORAGE ，则在这里没关系，因为您没有将数据库放在外部存储上
and the group permisson
I have no idea what that means, sorry. 我不知道那意味着什么，对不起。
Also, please consider using SQLiteOpenHelper , to be able to handle database schema changes over time. 另外，请考虑使用SQLiteOpenHelper ，以便能够随时间处理数据库架构更改。
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