无法在Android SQlite数据库中插入数据

我无法在Android Sqlite数据库中插入记录，抛出的异常如下所示：

07-28 14:22:08.781: E/Database(403): Error inserting id=1 phone_number=999000 name=John
07-28 14:22:08.781: E/Database(403): android.database.sqlite.SQLiteConstraintException: error code 19: constraint failed
07-28 14:22:08.781: E/Database(403):    at android.database.sqlite.SQLiteStatement.native_execute(Native Method)
07-28 14:22:08.781: E/Database(403):    at android.database.sqlite.SQLiteStatement.execute(SQLiteStatement.java:61)
07-28 14:22:08.781: E/Database(403):    at android.database.sqlite.SQLiteDatabase.insertWithOnConflict(SQLiteDatabase.java:1582)
07-28 14:22:08.781: E/Database(403):    at android.database.sqlite.SQLiteDatabase.insert(SQLiteDatabase.java:1426)
07-28 14:22:08.781: E/Database(403):    at com.example.dbtest.DBHelper.insertContact(DBHelper.java:47)
07-28 14:22:08.781: E/Database(403):    at com.example.dbtest.MainActivity.onCreate(MainActivity.java:22)
07-28 14:22:08.781: E/Database(403):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
07-28 14:22:08.781: E/Database(403):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
07-28 14:22:08.781: E/Database(403):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
07-28 14:22:08.781: E/Database(403):    at android.app.ActivityThread.access$1500(ActivityThread.java:117)
07-28 14:22:08.781: E/Database(403):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
07-28 14:22:08.781: E/Database(403):    at android.os.Handler.dispatchMessage(Handler.java:99)
07-28 14:22:08.781: E/Database(403):    at android.os.Looper.loop(Looper.java:123)
07-28 14:22:08.781: E/Database(403):    at android.app.ActivityThread.main(ActivityThread.java:3683)
07-28 14:22:08.781: E/Database(403):    at java.lang.reflect.Method.invokeNative(Native Method)
07-28 14:22:08.781: E/Database(403):    at java.lang.reflect.Method.invoke(Method.java:507)
07-28 14:22:08.781: E/Database(403):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
07-28 14:22:08.781: E/Database(403):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
07-28 14:22:08.781: E/Database(403):    at dalvik.system.NativeStart.main(Native Method)
07-28 14:22:08.781: D/ContactsMaster ::(403): inserted

insertQuery函数在下面列出：

public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_NAME + "(" + KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT," + KEY_PH_NO + " TEXT" + ")";
        db.execSQL(CREATE_CONTACTS_TABLE);
    }


public void insertContact(){
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();

        values.put(KEY_ID, "1");
        values.put(KEY_NAME, "Rajan");
        values.put(KEY_PH_NO, "9990008973");

        db.insert(TABLE_NAME, null, values);
        db.close();
    }

执行时的代码返回异常。数据库创建成功，但是我无法将记录插入其中。