我正在尝试执行一个名为getLastFeatureUpdate的存储过程。
我将在下面逐一解释这个问题:
我在SQL中创建了如下表:
CREATE TABLE testTable
(
DayTime INT NOT NULL, /*yyddhhmm, 1010102345*/
FeatureNbr SMALLINT NOT NULL,
Val FLOAT(53) NOT NULL
);我现在已经创建了一个名为getLastFeatureUpdate的存储过程。这里需要注意的是,我使用了两个参数@maxDateTime和@tableName,因为它们每次都是不同的。然后,我将在后面的C#代码中传递这两个参数。
存储过程(如果我从过程和C#代码中删除C#)。那么,代码确实起作用)
CREATE PROCEDURE getLastFeatureUpdate
@maxDateTime float(53) = 0,
@tableName text
AS
SELECT
test.FeatureNbr,
test.DayTime,
test.Val
FROM
@tableName test
WHERE
DayTime = (SELECT MAX(DayTime)
FROM @tableName
WHERE FeatureNbr = test.FeatureNbr --This is what you are missing
AND DayTime <= @maxDateTime) --10102248我想从C#返回数据的testTable代码。如:MessageBox.Show(d1 + "," + d2 + "," + d3);所示
但这是我得到错误的地方:
过程或函数getLastFeatureUpdate指定的参数太多
注意,如果我没有在这里传递@tableName的第2行,代码就会正常工作(然后我必须删除@tableName作为存储过程getLastFeatureUpdate中的参数)。
cmd.Parameters.Add(new SqlParameter("@maxDateTime", 10102248));
cmd.Parameters.Add(new SqlParameter("@tableName", "testTable")); //If not using this parameter, the code will workC#代码:
void getLastFeatureUpdate()
{
using (SqlConnection conn = new SqlConnection(GetConnectionString()))
{
conn.Open();
// 1. create a command object identifying the stored procedure
SqlCommand cmd = new SqlCommand("getLastFeatureUpdate", conn);
// 2. set the command object so it knows to execute a stored procedure
cmd.CommandType = CommandType.StoredProcedure;
// 3. add parameter to command, which will be passed to the stored procedure
cmd.Parameters.Add(new SqlParameter("@maxDateTime", 10102248));
cmd.Parameters.Add(new SqlParameter("@tableName", "testTable")); //If not using this parameter, the code will work
// execute the command
using (SqlDataReader rdr = cmd.ExecuteReader())
{
// iterate through results, printing each to console
while (rdr.Read())
{
int v1 = (int)rdr["DayTime"];
int v2 = (Int16)rdr["FeatureNbr"];
double v3 = (double)rdr["Val"];
MessageBox.Show(v1 + "," + v2 + "," + v3);
}
}
}
}
static private string GetConnectionString()
{
return "Data Source=(LocalDB)\\MSSQLLocalDB;AttachDbFilename=C:\\Users\\andre\\source\\repos\\TestDatabaseCreation\\DatabaseTest.mdf;Integrated Security=True;Connect Timeout=30";
}发布于 2020-10-06 15:25:55
不能参数化Server中的表名,因此: SQL无效,而且CREATE PROC实际上没有运行。旧proc的内容是什么:只有您可以知道,但是:它不是显示的代码。它可能是一个虚拟版本,您在某一阶段的开发。试着打字:
exec sp_helptext getLastFeatureUpdate;具体来说,服务器应该告诉您:
Msg 1087, Level 16, State 1, Procedure getLastFeatureUpdate, Line 12 [Batch Start Line 0]
Must declare the table variable "@tableName".
Msg 1087, Level 16, State 1, Procedure getLastFeatureUpdate, Line 19 [Batch Start Line 0]
Must declare the table variable "@tableName".https://stackoverflow.com/questions/64228888
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