android中操作SQLite常见错误，androidsqlite

android中操作SQLite常见错误，androidsqlite

1.  android.database.sqlite.SQLiteException: unable to close due to unfinalised statements

FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.evaluation/com.evaluation.VehicleActivity}: android.database.sqlite.SQLiteException: unable to close due to unfinalised statements
	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2781)
	at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2797)
	at android.app.ActivityThread.access$2300(ActivityThread.java:135)
	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2132)
	at android.os.Handler.dispatchMessage(Handler.java:99)
	at android.os.Looper.loop(Looper.java:143)
	at android.app.ActivityThread.main(ActivityThread.java:4914)
	at java.lang.reflect.Method.invokeNative(Native Method)
	at java.lang.reflect.Method.invoke(Method.java:521)
	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
	at dalvik.system.NativeStart.main(Native Method)
Caused by: android.database.sqlite.SQLiteException: unable to close due to unfinalised statements
	at android.database.sqlite.SQLiteDatabase.dbclose(Native Method)
	at android.database.sqlite.SQLiteDatabase.onAllReferencesReleased(SQLiteDatabase.java:363)
	at android.database.sqlite.SQLiteClosable.releaseReference(SQLiteClosable.java:45)
	at android.database.sqlite.SQLiteProgram.onAllReferencesReleased(SQLiteProgram.java:116)
	at android.database.sqlite.SQLiteClosable.releaseReference(SQLiteClosable.java:45)
	at android.database.sqlite.SQLiteProgram.close(SQLiteProgram.java:293)
	at android.database.sqlite.SQLiteQuery.close(SQLiteQuery.java:133)
	at android.database.sqlite.SQLiteCursor.close(SQLiteCursor.java:532)
	at com.DatabaseHelper.selectAssessInformation(DatabaseHelper.java:338)
	at com.JSKApplication.selectAssessInformation(JSKApplication.java:631)
	at com.VehicleActivity.onCreate(VehicleActivity.java:548)
	at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1065)
	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2745)
	... 11 more

这个错误翻译过来就是：不能关闭数据库由于未完成的语句。

最可能的原因是：你在操作sqlite数据库时使用多线程了，但sqlite数据库是不支持多线程操作，所以你必须实现多线程同步的机制。

2.android.database.sqlite.SQLiteConstraintException: error code 19: constraint failed

约束失败，导致这类错误，原因一般有两个：

1)插入的数据有一个是主键，而且插入的主键相同；

2)插入的数据有一条数据为空，而数据库中定义不能为空，也会导致这样的错误；

3. close() was never explicitly called on database 

10-09 19:24:41.269: E/Database(1269): close() was never explicitly called on database '/data/data/com.android.providers.media/databases/external-47cd50a6.db' 
10-09 19:24:41.269: E/Database(1269): android.database.sqlite.DatabaseObjectNotClosedException: Application did not close the cursor or database object that was opened here 
10-09 19:24:41.269: E/Database(1269): at android.database.sqlite.SQLiteDatabase.<init>(SQLiteDatabase.java:1847) 
10-09 19:24:41.269: E/Database(1269): at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:820) 
10-09 19:24:41.269: E/Database(1269): at 

对于Android中的SQLite数据库，我一般采用的方法是，随用随取随关。 
进行DAO操作时，首先获取一个SQLiteDatabase对象，具体代码采用try{}finally{}的格式。确保有任何问题，数据库对象都被关闭。