C# 在c上检索存储过程的结果#
我有一个存储过程,它选择并返回年份列表。在sql server中,我这样称呼它:C# 在c上检索存储过程的结果#,c#,sql,asp.net,C#,Sql,Asp.net,我有一个存储过程,它选择并返回年份列表。在sql server中,我这样称呼它: DECLARE @return_value int EXEC @return_value = [dbo].[TestName] @del= 0 SELECT 'Return Value' = @return_value USE [TestTable] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO ALTER PROCEDURE
DECLARE @return_value int
EXEC @return_value = [dbo].[TestName]
@del= 0
SELECT 'Return Value' = @return_value
USE [TestTable]
GO
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE [dbo].[TestName] (@delvarchar(7))
AS
BEGIN
SELECT YEAR( [added]) AS year FROM [MyTable]
GROUP BY YEAR( [added])
ORDER BY YEAR( [added]) DESC
END
public List<string> getYears(string constr, int del)
{
using (var conn = new SqlConnection(constr))
using (var command = new SqlCommand("TestName", conn)
{
CommandType = CommandType.StoredProcedure
})
{
command.Parameters.AddWithValue("@del", del);
List<string> retunvalue = new List<string>();
conn.Open();
SqlDataReader reader;
reader = command.ExecuteReader();
conn.Close();
return retunvalue;
}
}
以便接收列表
我的SP如下所示:
DECLARE @return_value int
EXEC @return_value = [dbo].[TestName]
@del= 0
SELECT 'Return Value' = @return_value
USE [TestTable]
GO
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE [dbo].[TestName] (@delvarchar(7))
AS
BEGIN
SELECT YEAR( [added]) AS year FROM [MyTable]
GROUP BY YEAR( [added])
ORDER BY YEAR( [added]) DESC
END
public List<string> getYears(string constr, int del)
{
using (var conn = new SqlConnection(constr))
using (var command = new SqlCommand("TestName", conn)
{
CommandType = CommandType.StoredProcedure
})
{
command.Parameters.AddWithValue("@del", del);
List<string> retunvalue = new List<string>();
conn.Open();
SqlDataReader reader;
reader = command.ExecuteReader();
conn.Close();
return retunvalue;
}
}
不过,我想从c#中执行同样的操作,并将值传递到列表中
我尝试的是:
using (var conn = new SqlConnection(constr))
using (var command = new SqlCommand("TestName", conn)
{
CommandType = CommandType.StoredProcedure
})
{
command.Parameters.AddWithValue("@del", del);
SqlParameter retval = command.Parameters.Add("@return_value", SqlDbType.VarChar);
retval.Direction = ParameterDirection.ReturnValue;
conn.Open();
command.ExecuteNonQuery();
int retunvalue = (int)command.Parameters["@return_value"].Value;
conn.Close();
return retunvalue;
}
但是,它不返回任何值,而是只返回0
。我做错了什么?如何在指定的变量中获取列表
按照John Hanna的建议编辑代码我有如下建议:
DECLARE @return_value int
EXEC @return_value = [dbo].[TestName]
@del= 0
SELECT 'Return Value' = @return_value
USE [TestTable]
GO
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE [dbo].[TestName] (@delvarchar(7))
AS
BEGIN
SELECT YEAR( [added]) AS year FROM [MyTable]
GROUP BY YEAR( [added])
ORDER BY YEAR( [added]) DESC
END
public List<string> getYears(string constr, int del)
{
using (var conn = new SqlConnection(constr))
using (var command = new SqlCommand("TestName", conn)
{
CommandType = CommandType.StoredProcedure
})
{
command.Parameters.AddWithValue("@del", del);
List<string> retunvalue = new List<string>();
conn.Open();
SqlDataReader reader;
reader = command.ExecuteReader();
conn.Close();
return retunvalue;
}
}
public List getYears(string constr,int del)
{
使用(var conn=new SqlConnection(contr))
使用(var命令=新的SqlCommand(“TestName”,conn)
{
CommandType=CommandType.StoredProcess
})
{
command.Parameters.AddWithValue(“@del”,del);
List retunvalue=新列表();
conn.Open();
SqlDataReader;
reader=command.ExecuteReader();
康涅狄格州关闭();
返回返回值;
}
}
通过添加断点来浏览阅读器
,我发现它只包含错误:
Depth='(读卡器).Depth'引发了类型为“System.InvalidOperationException”的异常
至于克里希纳的回答,
dtList
是空的,计数为0,我不知道如何实现巴东的建议。你不应该使用ExecuteOnQuery,而应该使用ExecuteDataSet,如下所示:
public List<DSM_DocPropIdentify> GetDocPropIdentify(string docPropIdentifyID, string action, out string errorNumber)
{
errorNumber = string.Empty;
List<DSM_DocPropIdentify> docPropIdentifyList = new List<DSM_DocPropIdentify>();
DatabaseProviderFactory factory = new DatabaseProviderFactory();
SqlDatabase db = factory.CreateDefault() as SqlDatabase;
using (DbCommand dbCommandWrapper = db.GetStoredProcCommand("GetDocPropIdentify"))
{
// Set parameters
db.AddInParameter(dbCommandWrapper, "@DocPropIdentifyID", SqlDbType.VarChar, docPropIdentifyID);
db.AddOutParameter(dbCommandWrapper, spStatusParam, DbType.String, 10);
// Execute SP.
DataSet ds = db.ExecuteDataSet(dbCommandWrapper);
if (!db.GetParameterValue(dbCommandWrapper, spStatusParam).IsNullOrZero())
{
// Get the error number, if error occurred.
errorNumber = db.GetParameterValue(dbCommandWrapper, spStatusParam).PrefixErrorCode();
}
else
{
if (ds.Tables[0].Rows.Count > 0)
{
DataTable dt1 = ds.Tables[0];
docPropIdentifyList = dt1.AsEnumerable().Select(reader => new DSM_DocPropIdentify
{
DocPropIdentifyID = reader.GetString("DocPropIdentifyID"),
DocPropertyID = reader.GetString("DocPropertyID"),
DocCategoryID = reader.GetString("DocCategoryID"),
DocTypeID = reader.GetString("DocTypeID"),
OwnerID = reader.GetString("OwnerID"),
IdentificationCode = reader.GetString("IdentificationCode"),
IdentificationSL = reader.GetString("IdentificationSL"),
AttributeGroup = reader.GetString("AttributeGroup"),
IdentificationAttribute = reader.GetString("IdentificationAttribute"),
IsRequired = reader.GetInt16("IsRequired"),
IsAuto = reader.GetInt16("IsAuto"),
SetOn = reader.GetString("SetOn"),
SetBy = reader.GetString("SetBy"),
ModifiedOn = reader.GetString("ModifiedOn"),
ModifiedBy = reader.GetString("ModifiedBy"),
Status = reader.GetInt32("Status"),
Remarks = reader.GetString("Remarks")
}).ToList();
}
}
}
return docPropIdentifyList;
}
public List getdocpropidentity(string docpropidentifid、string action、out string errorNumber)
{
errorNumber=string.Empty;
List docpropidentitylist=新列表();
DatabaseProviderFactory=新的DatabaseProviderFactory();
SqlDatabase db=factory.CreateDefault()作为SqlDatabase;
使用(DbCommand dbCommandWrapper=db.GetStoredProcCommand(“getdocpropidentity”))
{
//设置参数
db.AddInParameter(dbCommandWrapper,“@docpropIdentificationId”,SqlDbType.VarChar,docpropIdentificationId);
AddOutParameter(dbCommandWrapper,spStatusParam,DbType.String,10);
//执行SP。
数据集ds=db.ExecuteDataSet(dbCommandWrapper);
如果(!db.GetParameterValue(dbCommandWrapper,spStatusParam).IsNullOrZero())
{
//如果发生错误,请获取错误号。
errorNumber=db.GetParameterValue(dbCommandWrapper,spStatusParam).PrefixErrorCode();
}
其他的
{
如果(ds.Tables[0].Rows.Count>0)
{
DataTableDT1=ds.Tables[0];
docProIdentityList=dt1.AsEnumerable()。选择(读卡器=>new DSM_docProIdentity
{
docPropIdentificationId=reader.GetString(“docPropIdentificationId”),
DocPropertyID=reader.GetString(“DocPropertyID”),
DocCategoryID=reader.GetString(“DocCategoryID”),
DocTypeID=reader.GetString(“DocTypeID”),
OwnerID=reader.GetString(“OwnerID”),
IdentificationCode=reader.GetString(“IdentificationCode”),
IdentificationSL=reader.GetString(“IdentificationSL”),
AttributeGroup=reader.GetString(“AttributeGroup”),
IdentificationAttribute=reader.GetString(“IdentificationAttribute”),
IsRequired=reader.GetInt16(“IsRequired”),
IsAuto=reader.GetInt16(“IsAuto”),
SetOn=reader.GetString(“SetOn”),
SetBy=reader.GetString(“SetBy”),
ModifiedOn=reader.GetString(“ModifiedOn”),
ModifiedBy=reader.GetString(“ModifiedBy”),
Status=reader.GetInt32(“Status”),
备注=reader.GetString(“备注”)
}).ToList();
}
}
}
返回docpropidentitylist;
}
是dbo.TestName返回一个表或值。如果返回一个表,那么您必须执行DataAdapter或DataReader。你应该替换上面的陈述
作为
然后您可以遍历datatable并将其添加到列表中
List<Object> listObj=new List<Object>();
foreach(var rows in dtList.Rows)
{
listObj.Add(rows["Column_name"]);
}
返回多个表。您可以删除冗余的最后一条语句
SELECT 'Return Value' = @return_value
现在将使用值填充datatable
让我知道这是否有效。ExecuteNonQuery()
之所以被称为ExecuteNonQuery(),是因为它用于不查询数据的东西。返回的0
是命令更改的行数
相反,使用ExecuteReader()
,您将返回一个SqlDataReader
对象,您可以调用该对象来遍历行,然后检查每个行的详细信息
如果要将其返回到另一个方法,请使用ExecuteReader(CommandBehavior.CloseConnection)
,然后在完成连接后,使用读取器而不是Close()
或Dispose()
关闭连接,然后读取器将关闭连接
如果只有一行有一列(或者出于某种原因,只关心第一行的第一列,即使有更多列),那么
ExecuteScalar()
是一种只获取单个值的方便方法。该C#代码对于读取返回值来说看起来是正确的。您应该发布SP,因为问题可能在那里(例如,您可能使用SELECT而不是RETURN返回值)。嗨,Jon,我编辑了我的问题,包括尝试您的建议得到的结果。我的建议也包括调用Read()
。继续调用Read()