SQLite auto increment not working

问题

ok this isn't spamming and it's supposed to be simple I don't know why it's not working this is my code:

gamesdatabase = openOrCreateDatabase("GamesDatabase", MODE_PRIVATE, null);
gamesdatabase.execSQL("CREATE TABLE IF NOT EXISTS Games (ID INTEGER PRIMARY KEY, Name
VARACHAR, NPlayers INT(1), NRounds INT(2), WinScore INT(2));");

gamesdatabase.execSQL("INSERT INTO Games 
(ID, Name, NPlayers, NRounds, WinScore ) VALUES ( NULL, 'TAWLA',2,0,0 );");

gamesdatabase.execSQL("INSERT INTO Games 
(ID, Name, NPlayers, NRounds, WinScore ) VALUES ( NULL, 'DOMANA',4,0,0 );");


Cursor c = gamesdatabase.rawQuery("SELECT * FROM Games", null);
c.moveToFirst();
while (c.isAfterLast() == false) {
Log.d("BEZRA", String.valueOf(c.getInt(c.getColumnIndex("ID"))));
c.moveToNext();
}

what's wrong with this ? the log displays 0 for all records

回答1:

The primary key for SQLite tables is called _id. It is auto incrementing, and you should not be trying to insert values into it.

gamesdatabase = openOrCreateDatabase("GamesDatabase", MODE_PRIVATE, null);
gamesdatabase.execSQL("CREATE TABLE IF NOT EXISTS Games (_id INTEGER PRIMARY KEY, Name
VARACHAR, NPlayers INT(1), NRounds INT(2), WinScore INT(2));");

gamesdatabase.execSQL("INSERT INTO Games 
(Name, NPlayers, NRounds, WinScore ) VALUES ('TAWLA',2,0,0 );");

gamesdatabase.execSQL("INSERT INTO Games 
(Name, NPlayers, NRounds, WinScore ) VALUES ('DOMANA',4,0,0 );");


Cursor c = gamesdatabase.rawQuery("SELECT * FROM Games", null);
c.moveToFirst();
while (c.isAfterLast() == false) {
Log.d("BEZRA", String.valueOf(c.getInt(c.getColumnIndex("_id"))));
c.moveToNext();
}

回答2:

What worked for me was renaming my create type from INT to INTEGER and it started working.

From this:

CREATE TABLE IF NOT EXISTS foo (id INT PRIMARY KEY, bar INT)

to this:

CREATE TABLE IF NOT EXISTS foo (id INTEGER PRIMARY KEY, bar INT)

回答3:

c.getColumnIndex("ID") gets the index of the column, which ID is 0 indexed column, Name is 1 etc

you want

c.getInt(c.getColumnIndex("ID"))

回答4:

You can see http://alvinalexander.com/android/sqlite-autoincrement-serial-identity-primary-key Example CRETAE_TABLE

  CREATE TABLE salespeople (
  id INTEGER PRIMARY KEY,
  first_name TEXT NOT NULL,
  last_name TEXT NOT NULL,
  commission_rate REAL NOT NULL
);

INSERT_DATA

 INSERT INTO salespeople VALUES (null, 'Fred', 'Flinstone', 10.0);

---OR---

INSERT INTO salespeople (first_name, last_name, commission_rate) VALUES ('Fred', 'Flinstone', 10.0);

回答5:

You want to tell it that the column is auto incrementing.

ID INTEGER PRIMARY KEY AUTO_INCREMENT NOT NULL

instead.

回答6:

Because You didn't set it to auto increment. Primary key is not enough.

CREATE TABLE IF NOT EXISTS Games (ID INTEGER PRIMARY KEY AUTOINCREMENT, Name VARACHAR, NPlayers INT(1), NRounds INT(2), WinScore INT(2));

来源：https://stackoverflow.com/questions/16832401/sqlite-auto-increment-not-working

标签

android

database

sqlite

auto-increment