我必须将数据移动到一个表到另一个表。新表将与旧表一样,但没有约束(冲突替换),因此列相同。
这是我必须做的查询:INSERT INTO TABLE2 SELECT * FROM TABLE1
遇到了一个大问题,因为我认为我无法通过以下方式执行此类查询:
db.execSQL("INSERT INTO " + Tables.TRACKS + "_2 SELECT * FROM " + Tables.TRACKS );
execSQL 失败并显示此错误 ( db onUpgrade ):
06-04 12:25:50.000: D/SqliteDatabaseCpp(17817): Registering sqlite logging func: /data/data/com.musixmatch.android.lyrify/databases/library.db
06-04 12:25:50.000: D/SqliteDatabaseCpp(17817): DB info: open db, path = /data/data/com.musixmatch.android.lyrify/databases , key = lafvYvq, flag = 6, file size = 101376
06-04 12:25:50.000: D/SqliteDatabaseCpp(17817): DB info: path = /data/data/com.musixmatch.android.lyrify/databases , key = lafvYvq, handle: 0x1bd8bd8, type: w, r/w: (0,1), mode: delete, disk free size: 1243 M
06-04 12:25:50.010: D/SqliteDatabaseCpp(17817): DB info: close db, path = /data/data/com.musixmatch.android.lyrify/databases , key = lafvYvq, handle = 0x1bd8bd8, type = w, r/w = (0, 0)
06-04 12:25:50.030: E/SQLiteOpenHelper(17817): Couldn't open library.db for writing (will try read-only):
06-04 12:25:50.030: E/SQLiteOpenHelper(17817): android.database.sqlite.SQLiteConstraintException: error code 19: constraint failed
06-04 12:25:50.030: E/SQLiteOpenHelper(17817): at android.database.sqlite.SQLiteStatement.native_execute(Native Method)
06-04 12:25:50.030: E/SQLiteOpenHelper(17817): at android.database.sqlite.SQLiteStatement.executeUpdateDelete(SQLiteStatement.java:95)
06-04 12:25:50.030: E/SQLiteOpenHelper(17817): at android.database.sqlite.SQLiteDatabase.executeSql(SQLiteDatabase.java:2008)
06-04 12:25:50.030: E/SQLiteOpenHelper(17817): at android.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1948)
06-04 12:25:50.030: E/SQLiteOpenHelper(17817): at com.designfuture.music.provider.MusicDatabase.alterTrackFragmentForFileIDSupport(MusicDatabase.java:316)
06-04 12:25:50.030: E/SQLiteOpenHelper(17817): at com.designfuture.music.provider.MusicDatabase.onUpgrade(MusicDatabase.java:242)
06-04 12:25:50.030: E/SQLiteOpenHelper(17817): at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:188)
06-04 12:25:50.030: E/SQLiteOpenHelper(17817): at android.database.sqlite.SQLiteOpenHelper.getReadableDatabase(SQLiteOpenHelper.java:249)
06-04 12:25:50.030: E/SQLiteOpenHelper(17817): at com.designfuture.music.provider.MusicProvider.query(MusicProvider.java:199)
06-04 12:25:50.030: E/SQLiteOpenHelper(17817): at android.content.ContentProvider$Transport.query(ContentProvider.java:189)
06-04 12:25:50.030: E/SQLiteOpenHelper(17817): at android.content.ContentResolver.query(ContentResolver.java:315)
06-04 12:25:50.030: E/SQLiteOpenHelper(17817): at android.content.AsyncQueryHandler$WorkerHandler.handleMessage(AsyncQueryHandler.java:94)
06-04 12:25:50.030: E/SQLiteOpenHelper(17817): at android.os.Handler.dispatchMessage(Handler.java:99)
06-04 12:25:50.030: E/SQLiteOpenHelper(17817): at android.os.Looper.loop(Looper.java:156)
06-04 12:25:50.030: E/SQLiteOpenHelper(17817): at android.os.HandlerThread.run(HandlerThread.java:60)
06-04 12:25:50.030: D/SqliteDatabaseCpp(17817): DB info: open db, path = /data/data/com.musixmatch.android.lyrify/databases , key = lafvYvq, flag = 1, file size = 101376
06-04 12:25:50.030: D/SqliteDatabaseCpp(17817): DB info: path = /data/data/com.musixmatch.android.lyrify/databases , key = lafvYvq, handle: 0x1bec760, type: r, r/w: (1,0), mode: delete, disk free size: 1243 M
06-04 12:25:50.030: D/SqliteDatabaseCpp(17817): DB info: close db, path = /data/data/com.musixmatch.android.lyrify/databases , key = lafvYvq, handle = 0x1bec760, type = r, r/w = (0, 0)
06-04 12:25:50.040: W/AsyncQuery(17817): Exception thrown during handling EVENT_ARG_QUERY
06-04 12:25:50.040: W/AsyncQuery(17817): android.database.sqlite.SQLiteException: Can't upgrade read-only database from version 7 to 9: /data/data/com.musixmatch.android.lyrify/databases/library.db
06-04 12:25:50.040: W/AsyncQuery(17817): at android.database.sqlite.SQLiteOpenHelper.getReadableDatabase(SQLiteOpenHelper.java:262)
06-04 12:25:50.040: W/AsyncQuery(17817): at com.designfuture.music.provider.MusicProvider.query(MusicProvider.java:199)
06-04 12:25:50.040: W/AsyncQuery(17817): at android.content.ContentProvider$Transport.query(ContentProvider.java:189)
06-04 12:25:50.040: W/AsyncQuery(17817): at android.content.ContentResolver.query(ContentResolver.java:315)
06-04 12:25:50.040: W/AsyncQuery(17817): at android.content.AsyncQueryHandler$WorkerHandler.handleMessage(AsyncQueryHandler.java:94)
06-04 12:25:50.040: W/AsyncQuery(17817): at android.os.Handler.dispatchMessage(Handler.java:99)
06-04 12:25:50.040: W/AsyncQuery(17817): at android.os.Looper.loop(Looper.java:156)
06-04 12:25:50.040: W/AsyncQuery(17817): at android.os.HandlerThread.run(HandlerThread.java:60)
我认为这是因为我在查询中有一个选择......这是来自Android文档:http://developer.android.com/reference/android/database/sqlite/SQLiteDatabase.html#execSQL%28java.lang.String%29
执行不是 SELECT 或任何其他 SQL 的单个 SQL 语句 返回数据的语句。
如果我使用
db.rawQuery( "INSERT INTO " + Tables.TRACKS + "_2 SELECT * FROM " + Tables.TRACKS, null );
它执行没有错误,但它不做任何事情。我认为这是因为 rawQuery 用于执行 SELECT 查询并且不会写入数据库。
更新:如果我使用普通查询选择所有记录,则通过循环将它们插入新表中一切正常,但这不是优化的方式,我不想有一个缓慢的升级应用程序
UPDATE2:
以下是这两个表之间的唯一区别:
新表有 3 个新字符串列,它们可以为空新表不会有旧表具有的唯一(冲突替换)约束
两个表都有以下字段:BaseColumns._ID + " INTEGER PRIMARY KEY AUTOINCREMENT"
。我必须从插入中排除该字段吗?另请记住,第二个平板电脑在升级时是空的(我在升级时创建它)
那么,我该怎么做才能执行需要与我的查询同时写入和读取的查询呢?
由于您没有发布表格布局,因此让我们从以下内容开始:
CREATE TABLE TABLE1 (
_id INTEGER PRIMARY KEY,
value1 TEXT,
value2 TEXT
);
CREATE TABLE TABLE2 (
_id INTEGER PRIMARY KEY,
value2 TEXT,
value1 TEXT,
value3 TEXT,
value4 TEXT,
value5 TEXT
);
要正确地将TABLE1
中的值插入到TABLE2
中,您必须考虑顺序和列数很重要并且必须匹配(如果您有主键,最好从 insert & select 语句中省略它们 - 不要四处复制这样的东西)。
INSERT INTO TABLE2 (value1, value2) SELECT value1, value2 FROM TABLE1