Question

好吧，这不是垃圾邮件，它应该很简单，我不知道它为什么不起作用这是我的代码：

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();
}

这有什么问题？所有记录的日志显示为0

Answer 1

SQLite表的主键称为_id。它是自动递增的，您不应该尝试在其中插入值。

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();
}

Answer 2

对我有用的是将我的创建类型从INT重命名为INTEGER并开始工作。

由此：

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

到此：

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

Answer 3

c.getColumnIndex("ID") 获取列的索引，其中ID为0索引列，名称为1等

你想要

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

Answer 4

你可以看到 http://alvinalexander.com/android/sqlite-autoincrement-serial-identity-primary-key 示例 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);

Answer 5

您想告诉它该列是自动递增的。

ID INTEGER PRIMARY KEY AUTO_INCREMENT NOT NULL

代替。

Answer 6

因为您没有将其设置为自动增量。主键是不够的。

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

SQLite自动增量不起作用

6 个答案: