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问题描述
如何从SQL查询返回数组维?或可以使用二维列表?
这是我的代码,但是我不知道要从SQLiteDataReader获取列名
How to return array dimensional from SQL Query? or can use 2 dimensional List?
here my code , but I dont have any idea for get column name from SQLiteDataReader
public string[][] Select(string query)
{
string[,] data = new string[100, 100];
int i;
if (this.OpenConnection() == true)
{ //Create Command
SQLiteCommand cmd = new SQLiteCommand(query, con);
//Create a data reader and Execute the command
SQLiteDataReader dataReader = cmd.ExecuteReader();
while (dataReader.Read())
{
i++;
data["title"][i] = dataReader["title"][i];
data["author"][i]= dataReader["author"][i];
data["isbn"][i] = dataReader["isbn"][i];
}
return data;
//close Data Reader
dataReader.Close();
//close Connection
this.CloseConnection();
}
推荐答案
//create class as below
public class Book
{
public string Title { get; set; }
public string Author { get; set; }
public string Isbn { get; set; }
}
//change your method to return list of books
//when you call, set the query as "select titlle, author, isbn from yourtable"
public List<Book> Select(string query)
{
List<Book> books = new List<Book>();
if (this.OpenConnection() == true)
{ //Create Command
SQLiteCommand cmd = new SQLiteCommand(query, con);
//Create a data reader and Execute the command
SQLiteDataReader dataReader = cmd.ExecuteReader();
while (dataReader.Read())
{
Book book = new Book();
book.Title = dataReader[0] as string;
book.Author = dataReader[1] as string;
book.Isbn = dataReader[2] as string;
books.Add(book);
}
//close Data Reader
dataReader.Close();
//close Connection
this.CloseConnection();
return books;
}
}
//create class as below
public class Book
{
public string Title { get; private set; }
public string Author { get; private set; }
public string Isbn { get; private set; }
public Book ( System.Data.IDataRecord Data )
{
Title = (string) Data [ 0 ] ;
Author = (string) Data [ 1 ] ;
Isbn = (string) Data [ 2 ] ;
}
}
public List<Book> Select(string query)
{
List<Book> books = new List<Book>();
if (this.OpenConnection() )
{
using ( SQLiteCommand cmd = new SQLiteCommand(query, con) )
{
using ( SQLiteDataReader dataReader = cmd.ExecuteReader() )
{
while (dataReader.Read())
{
books.Add ( new Book ( dataReader ) ) ;
}
}
}
this.CloseConnection();
}
return books;
}
也许有一种使它通用的方法,但此刻它使我不知所措.
There may be a way to make it generic, but it escapes me at the moment.
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