升级SQLite数据库时出错

Question

I am trying to implement database upgrading for my android app. I tried to use following code:

// Create a table that is equivalent to the existing one but with one column as TEXT instead of INTEGER
db.execSQL("CREATE VIRTUAL TABLE distributors_new USING FTS3 (fname TEXT, lname TEXT, phoneNumber TEXT, email TEXT, notes TEXT, parentid INTEGER, customid TEXT FOREIGN KEY (parentid) REFERENCES distributors(rowid) ON DELETE CASCADE ON UPDATE CASCADE);");
//Insert all data from the old table to the new one.
db.execSQL("INSERT INTO distributors_new SELECT * FROM distributors;");
// Drop the old table
db.execSQL("DROP TABLE distributors;");
// Rename the new table
db.execSQL("ALTER TABLE distributors_new RENAME TO distributors;");

However I got an error after the onUpgrade method is executed.

02-12 16:31:16.324: ERROR/Database(1456): Failure 1 (SQL logic error or missing database) on 0x26b338 when executing 'COMMIT;'
02-12 16:31:16.334: ERROR/SQLiteOpenHelper(1456): Couldn't open mlmDB for writing (will try read-only):
02-12 16:31:16.334: ERROR/SQLiteOpenHelper(1456): android.database.sqlite.SQLiteException: SQL logic error or missing database: COMMIT;
02-12 16:31:16.334: ERROR/SQLiteOpenHelper(1456)

What am I doing wrong?

Answer 1

我不是SQL方面的专家，但是在我看来，您好像没有连接到数据库服务器，或者您没有您认为的特权级别。

Answer 2

I added

db.beginTransaction();
// Code
db.endTransaction();

And now it seems to work.

Answer 3

There is, AFAIK, no reason to do this. Sqlite uses dynamic typing , so the data type when you create the table has little importance. It only affects the type affinity, check the linked documentation.

Answer 4

The failure may be due to 'putting 'NULL' into non NULL column '.

Source