Bug 25111 - Mono.Data.Sqlite Attempt to write a read-only database exception on x86_64 API 21
Summary: Mono.Data.Sqlite Attempt to write a read-only database exception on x86_64 AP...
Status: RESOLVED UPSTREAM
Alias: None
Product: Android
Classification: Xamarin
Component: BCL Class Libraries ()
Version: 4.20.0
Hardware: PC Mac OS
: --- normal
Target Milestone: ---
Assignee: Jonathan Pryor
URL:
Depends on:
Blocks:
 
Reported: 2014-12-05 12:40 UTC by John Miller [MSFT]
Modified: 2014-12-23 12:21 UTC (History)
2 users (show)

Tags:
Is this bug a regression?: ---
Last known good build:

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Status:
RESOLVED UPSTREAM

Description John Miller [MSFT] 2014-12-05 12:40:23 UTC
**Overview:**

   Mono.Data.Sqlite will throw exceptions that the database is read-only when running on API 21 x86_64 emulators. 

**Steps to Reproduce:**

   1. Create an Android 5.0 API 21 emulator using the Atom x86_64 (you will need Intel HAXM installed)
   2. Run the attached sample on that emulator

**Actual Results:**

   It will crash with an exception message "Attempt to write a read-only database". 

**Expected Results:**

   No crash.

**Build Date & Platform:**

   XA 4.20.0.28
   Mono 3.10
   Android 5.0 x86_64

**Additional Information:**

   I did not have a device that was 64 bit to test this on. It may not be specific to emulators. 
   It works on x86 emulators
   It works on 32 bit Android 5 devices. 
   The database file does not appear to be read-only (-rwxrwx--- root     sdcard_r    10240 2014-12-02 11:15 DatabaseName.db)
   
   Possible explanation: http://stackoverflow.com/a/27013698
   The SO article points to a bug report for the issue being in Sqlite: https://code.google.com/p/android/issues/detail?id=79994
Comment 2 Jonathan Pryor 2014-12-19 12:28:32 UTC
This appears to be an Android bug, in that 32-bit processes running on 64-bit targets can't access external directories:

http://stackoverflow.com/questions/26937152/workaround-for-nexus-9-sqlite-file-write-operations-on-external-dirs