是否可以从Sqlite查询返回动态对象或数据集？ [英] Is it possible to return dynamic objects or Dataset from a Sqlite Query?

问题描述

我在<$ c $中使用 Sqlite.Net c> Xamarin.Forms 应用程序。到目前为止，如果我的对象是这样的类，返回对象列表将非常有用：

I am using Sqlite.Net in my Xamarin.Forms application. So far it has been great at returning lists of objects if my object is a class like so:

SqliteDatabase.Connection.Query<Customer>("Select * from Customers");

我现在想动态返回 DataSet 的等价物从我的查询中

I would now like to return the equivalent of a DataSet dynamically from my query

SqliteDatabase.Connection.Query("Select * from Customers inner join Calls on Customers.Id=Calls.CustomerId")

现在从第二个查询中我想返回一个 DataSet 而不是对象列表。我知道我可以创建一个合并了 Customers 和 Calls 列的新对象，但是我不想拥有每次我想查询数据库时都会创建对象。

Now from the second query I would like to return a DataSet instead of a list of objects. I know I could create a new object which combines the columns of Customers and Calls but I don't want to have to create objects every time I want to query the database.

是否可以动态返回 Dataset 或 Object ？

推荐答案

最后，我实际上设法提出了一种方法运行任何查询，并将行作为列表中的项返回，将列作为数组中的对象返回：

In the end I actually managed to come up with a method that will run any query and return the rows as items in the list and the columns as objects in the array:

    public List<object[]> RunSql(string sqlString, bool includeColumnNamesAsFirstRow)
    {
        var lstRes = new List<object[]>();
        SQLitePCL.sqlite3_stmt stQuery = null;
        try
        {
            stQuery = SQLite3.Prepare2(fieldStrikeDatabase.Connection.Handle, sqlString);
            var colLenght = SQLite3.ColumnCount(stQuery);

            if (includeColumnNamesAsFirstRow)
            {
                var obj = new object[colLenght];
                lstRes.Add(obj);
                for (int i = 0; i < colLenght; i++)
                {
                    obj[i] = SQLite3.ColumnName(stQuery, i);
                }
            }

            while (SQLite3.Step(stQuery) == SQLite3.Result.Row)
            {
                var obj = new object[colLenght];
                lstRes.Add(obj);
                for (int i = 0; i < colLenght; i++)
                {
                     var columnType = SQLitePCL.raw.sqlite3_column_decltype(stQuery, i);

                     switch (columnType)
                     {
                         case "text":
                              obj[i] = SQLite3.ColumnString(stQuery, i);
                              break;
                         case "int":
                               obj[i] = SQLite3.ColumnInt(stQuery, i);
                               break;
                         case "real":
                               obj[i] = SQLite3.ColumnDouble(stQuery, i);
                               break;
                         case "blob":
                               obj[i] = SQLite3.ColumnBlob(stQuery, i);
                               break;
                         case "null":
                               obj[i] = null;
                               break;
                      }
                }
            }
            return lstRes;
        }
        catch (Exception)
        {
            return null;
        }
        finally
        {
            if (stQuery != null)
            {
                SQLite3.Finalize(stQuery); 
            }
        }
    }

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