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                        /Android攻城獅的第二門課（第3季）

為什么主鍵沒有自增長？?

代碼跟老師的一樣啊，為什么主鍵沒有自增長？都是NULL

SQLiteDatabase?db?=?openOrCreateDatabase("user.db",MODE_PRIVATE,null);
db.execSQL("create?table?if?not?exists?usertb?(_id?integer?not?null?primary?key?autoincrement,name?text?not?null,age?integer,sex?text?not?null)");
db.execSQL("insert?into?usertb(name,age,sex)?values('張三',18,'女')");
db.execSQL("insert?into?usertb(name,age,sex)?values('李四',19,'女')");
db.execSQL("insert?into?usertb(name,age,sex)?values('王五',20,'男')");
Cursor?c?=?db.rawQuery("select?*?from?usertb",null);
if(c!=null){
????while(c.moveToNext()){
????????Log.i("info","_id:"+c.getInt(c.getColumnIndex("_id")));
????????Log.i("info","name:"+c.getString(c.getColumnIndex("name")));
????????Log.i("info","age:"+c.getInt(c.getColumnIndex("age")));
????????Log.i("info","sex:"+c.getString(c.getColumnIndex("sex")));
????????Log.i("info","__________________________________");
????}
????c.close();
}
db.close();

打出來的結果ID全是0，navicat 里面看到ID全是null。。

06-12 05:53:30.405 26973-26973/com.geekband.sqllitedemo01 I/info: _id:0
06-12 05:53:30.405 26973-26973/com.geekband.sqllitedemo01 I/info: name:張三
06-12 05:53:30.405 26973-26973/com.geekband.sqllitedemo01 I/info: age:18
06-12 05:53:30.405 26973-26973/com.geekband.sqllitedemo01 I/info: sex:女
06-12 05:53:30.405 26973-26973/com.geekband.sqllitedemo01 I/info: __________________________________
06-12 05:53:30.405 26973-26973/com.geekband.sqllitedemo01 I/info: _id:0
06-12 05:53:30.405 26973-26973/com.geekband.sqllitedemo01 I/info: name:李四
06-12 05:53:30.405 26973-26973/com.geekband.sqllitedemo01 I/info: age:19
06-12 05:53:30.405 26973-26973/com.geekband.sqllitedemo01 I/info: sex:女
06-12 05:53:30.405 26973-26973/com.geekband.sqllitedemo01 I/info: __________________________________
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: _id:0
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: name:王五
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: age:20
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: sex:男
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: __________________________________
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: _id:0
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: name:張三
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: age:18
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: sex:女
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: __________________________________
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: _id:0
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: name:李四
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: age:19
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: sex:女
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: __________________________________
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: _id:0
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: name:王五
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: age:20
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: sex:男
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: __________________________________
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: _id:0
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: name:張三
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: age:18
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: sex:女
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: __________________________________
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: _id:0
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: name:李四
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: age:19
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: sex:女
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: __________________________________
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: _id:0
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: name:王五
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: age:20
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: sex:男
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: __________________________________
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: _id:0
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: name:張三
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: age:18
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: sex:女
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: __________________________________
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: _id:0
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: name:李四
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: age:19
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: sex:女
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: __________________________________
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: _id:0
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: name:王五
06-12 05:53:30.406 26973-26973/com.geekband.sqllitedemo01 I/info: age:20
06-12 05:53:30.407 26973-26973/com.geekband.sqllitedemo01 I/info: sex:男
06-12 05:53:30.407 26973-26973/com.geekband.sqllitedemo01 I/info: __________________________________
06-12 05:53:30.493 26973-27023/com.geekband.sqllitedemo01 D/OpenGLRenderer: Use EGL_SWAP_BEHAVIOR_PRESERVED: