C# 尝试获取具有相同 ID 但多个订单的数据
C# Trying to GET Data with the same ID but multiple orders
晚上好,
我在使用以下代码时遇到问题,它可以工作,但它只显示来自一个 ID 的一个订单:
namespace ProjectDatabase.Models
{
public class searchQuery
{
public AppDb Db { get; }
public searchQuery(AppDb db)
{
Db = db;
}
public async Task<search> FindAllAsync(int id)
{
using var cmd = Db.Connection.CreateCommand();
cmd.CommandText = @"...My Query";
cmd.Parameters.Add(new MySqlParameter
{
ParameterName = "@id_customer",
DbType = DbType.Int32,
Value = id,
});
var result = await ReadAllAsync(await cmd.ExecuteReaderAsync());
return result.Count > 0 ? result[0] : null;
}
public async Task<search> FindOneIdAsync(int id)
{
using var cmd = Db.Connection.CreateCommand();
cmd.CommandText = @"...My Query";
cmd.Parameters.Add(new MySqlParameter
{
ParameterName = "@id_customer",
DbType = DbType.Int32,
Value = id,
});
var result = await ReadAllAsync(await cmd.ExecuteReaderAsync());
return result.Count > 0 ? result[0] : null;
}
public async Task<List<search>> LatestSearchAsync()
{
using var cmd = Db.Connection.CreateCommand();
cmd.CommandText = @"... My Query";
return await ReadAllAsync(await cmd.ExecuteReaderAsync());
}
private async Task<List<search>> ReadAllAsync(DbDataReader reader)
{
var adb_search = new List<search>();
using (reader)
{
while (await reader.ReadAsync())
{
var search = new search(Db)
{
id_customer = reader.GetInt32(0),
delivery_person_name = reader.GetString(1),
firstname = reader.GetString(2),
lastname = reader.GetString(3),
email = reader.GetString(4),
order_number = reader.GetString(5),
};
adb_search.Add(search);
}
}
return adb_search;
}
}
}
这是将在 Postman 中显示的内容:
{
"id_customer": 88,
"delivery_person_name": "Name",
"firstname": "firstname",
"lastname": "lastname",
"email": "email",
"order_number": "order"
}
问题是这个 ID 为 88 的客户将完成更多订单,例如 50 个,但它只显示第一个订单,仅此而已。结束,其他49个订单不显示
这很奇怪,因为我在这 3 个查询中有另一个查询,它向我显示数据库中的所有用户,它工作正常并向我显示所有 100 个用户,但是对于订单查询,它只向我显示 1 个结果,仅此而已.
也许问题是我使用相同的结果来显示 2 个不同的查询?在你问之前,是的,我已经在 SQLyog 中测试了查询,它显示了 50 个订单,但在代码中它只显示了第一个订单。
在你判断之前,是的,我是 C# 的菜鸟。
谢谢,NewSounD。
问题是 FindAllAsync
return Task<search>
。你想要一个列表,所以你需要 return Task<List<search>>
.
这迫使您 return 只有一个 搜索 并编写此代码:return result.Count > 0 ? result[0] : null;
.
固定码:
public async Task<List<search>> FindAllAsync(int id)
{
using var cmd = Db.Connection.CreateCommand();
cmd.CommandText = @"...My Query";
cmd.Parameters.Add(new MySqlParameter
{
ParameterName = "@id_customer",
DbType = DbType.Int32,
Value = id,
});
var result = await ReadAllAsync(await cmd.ExecuteReaderAsync());
return result;
}
晚上好,
我在使用以下代码时遇到问题,它可以工作,但它只显示来自一个 ID 的一个订单:
namespace ProjectDatabase.Models
{
public class searchQuery
{
public AppDb Db { get; }
public searchQuery(AppDb db)
{
Db = db;
}
public async Task<search> FindAllAsync(int id)
{
using var cmd = Db.Connection.CreateCommand();
cmd.CommandText = @"...My Query";
cmd.Parameters.Add(new MySqlParameter
{
ParameterName = "@id_customer",
DbType = DbType.Int32,
Value = id,
});
var result = await ReadAllAsync(await cmd.ExecuteReaderAsync());
return result.Count > 0 ? result[0] : null;
}
public async Task<search> FindOneIdAsync(int id)
{
using var cmd = Db.Connection.CreateCommand();
cmd.CommandText = @"...My Query";
cmd.Parameters.Add(new MySqlParameter
{
ParameterName = "@id_customer",
DbType = DbType.Int32,
Value = id,
});
var result = await ReadAllAsync(await cmd.ExecuteReaderAsync());
return result.Count > 0 ? result[0] : null;
}
public async Task<List<search>> LatestSearchAsync()
{
using var cmd = Db.Connection.CreateCommand();
cmd.CommandText = @"... My Query";
return await ReadAllAsync(await cmd.ExecuteReaderAsync());
}
private async Task<List<search>> ReadAllAsync(DbDataReader reader)
{
var adb_search = new List<search>();
using (reader)
{
while (await reader.ReadAsync())
{
var search = new search(Db)
{
id_customer = reader.GetInt32(0),
delivery_person_name = reader.GetString(1),
firstname = reader.GetString(2),
lastname = reader.GetString(3),
email = reader.GetString(4),
order_number = reader.GetString(5),
};
adb_search.Add(search);
}
}
return adb_search;
}
}
}
这是将在 Postman 中显示的内容:
{
"id_customer": 88,
"delivery_person_name": "Name",
"firstname": "firstname",
"lastname": "lastname",
"email": "email",
"order_number": "order"
}
问题是这个 ID 为 88 的客户将完成更多订单,例如 50 个,但它只显示第一个订单,仅此而已。结束,其他49个订单不显示
这很奇怪,因为我在这 3 个查询中有另一个查询,它向我显示数据库中的所有用户,它工作正常并向我显示所有 100 个用户,但是对于订单查询,它只向我显示 1 个结果,仅此而已.
也许问题是我使用相同的结果来显示 2 个不同的查询?在你问之前,是的,我已经在 SQLyog 中测试了查询,它显示了 50 个订单,但在代码中它只显示了第一个订单。
在你判断之前,是的,我是 C# 的菜鸟。
谢谢,NewSounD。
问题是 FindAllAsync
return Task<search>
。你想要一个列表,所以你需要 return Task<List<search>>
.
这迫使您 return 只有一个 搜索 并编写此代码:return result.Count > 0 ? result[0] : null;
.
固定码:
public async Task<List<search>> FindAllAsync(int id)
{
using var cmd = Db.Connection.CreateCommand();
cmd.CommandText = @"...My Query";
cmd.Parameters.Add(new MySqlParameter
{
ParameterName = "@id_customer",
DbType = DbType.Int32,
Value = id,
});
var result = await ReadAllAsync(await cmd.ExecuteReaderAsync());
return result;
}