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 )";
//创建库
public MyHelper(Context context) {
super(context, "Gun_magazine.db", null, 2);
mContext=context;
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(sql);//创建表
db.execSQL(black);
Toast.makeText(mContext,"数据库创建成功",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");//这行报错
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;
}
解决方案 »
免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货