private Context mContext;
public static final String sql = "CREATE TABLE gun(" +
"_id INTEGER PRIMARY KEY AUTOINCREMENT," +
"BSSID TEXT,"+
"name TEXT ," +
"liable_person TEXT ," +
"date TEXT ," +
"state INTEGER )";
public static final String black="CREATE TABLE gunblack(" +
"_id INTEGER PRIMARY KEY AUTOINCREMENT," +
"BSSID TEXT )";
//創建庫
public MyHelper(Context context) {
super(context, "Gun_magazine.db", null, 2);
mContext=context;
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(sql);//創建表
db.execSQL(black);
Toast.makeText(mContext,"資料庫創建成功",Toast.LENGTH_SHORT).show();
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
}
使用：
public List<String> queryAll_black(){
SQLiteDatabase db=helper.getReadableDatabase();
Cursor c=db.query("gunblack",null,null,null,null,null,"_id DESC");//這行報錯
List<String> list=new ArrayList<String>();
while(c.moveToNext()){
long id=c.getLong(c.getColumnIndex("_id"));
String BSSID=c.getString(1);
list.add(BSSID);
}
c.close();
db.close();
return list;
}
uj5u.com熱心網友回復：
好像把以前的資料庫洗掉了可以運行了，麻煩個前輩了uj5u.com熱心網友回復：
gunblack表沒有創建成功uj5u.com熱心網友回復：
資料庫不用洗掉，只不過下次創建表或者其他操作時，可以將資料庫版本+1，然后把要進行的建表加欄位等操作放在onUpgrade方法中進行即可轉載請註明出處，本文鏈接：https://www.uj5u.com/yidong/91359.html
標籤：Android
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