小编San*_*eep的帖子

我试过这段代码

 Cursor c=db.rawQuery("SELECT name FROM sqlite_master WHERE type = 'table'",null);

 c.moveToFirst();

 while(!c.isAfterLast()){

Toast.makeText(activityName.this, "Table Name=> "+c.getString(0), Toast.LENGTH_LONG).show();

}

但它会引发错误 "android.database.sqlite.SQLiteException: no such table: sqlite_master(code 1):,while compiling: SELECT name FROM sqlite_master WHERE type='table'"

如何获取所有表名？帮我

提前致谢..

我想将HashMap转换为json数组,我的代码如下:

Map<String, String> map = new HashMap<String, String>();

map.put("first", "First Value");

map.put("second", "Second Value");

我试过这个但是没用.有解决方案吗

JSONArray mJSONArray = new JSONArray(Arrays.asList(map));

我有下面的查询,它正常工作,但不知道::在postgresql中的含义和用法.

select (
    select ( 
        case when 1 > 0 then 1::float / (
            select count(id) from transactions_products where transaction_id in (
            select id from transactions_transactions tt 
            where status = 3 and fi = 355 
                and (invoice_date >= 1420754400) 
                and (invoice_date <= 1421099999) 
                and (tt.division_id = 107) 
                and (tt.department_id = 210) 
        ) and is_vehicle = 1 
    )::float else 0 end)
 limit 1) as f_4