SqlCommand.Parameters 属性
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
public:
property System::Data::SqlClient::SqlParameterCollection ^ Parameters { System::Data::SqlClient::SqlParameterCollection ^ get(); };
public System.Data.SqlClient.SqlParameterCollection Parameters { get; }
[System.Data.DataSysDescription("DbCommand_Parameters")]
public System.Data.SqlClient.SqlParameterCollection Parameters { get; }
member this.Parameters : System.Data.SqlClient.SqlParameterCollection
[<System.Data.DataSysDescription("DbCommand_Parameters")>]
member this.Parameters : System.Data.SqlClient.SqlParameterCollection
Public ReadOnly Property Parameters As SqlParameterCollection
属性值
Transact-SQL 语句或存储过程的参数。 默认值为空集合。
- 属性
示例
以下示例演示如何创建 SqlCommand 并将参数添加到 SqlParameterCollection。
private static void UpdateDemographics(Int32 customerID,
string demoXml, string connectionString)
{
// Update the demographics for a store, which is stored
// in an xml column.
string commandText = "UPDATE Sales.Store SET Demographics = @demographics "
+ "WHERE CustomerID = @ID;";
using (SqlConnection connection = new SqlConnection(connectionString))
{
SqlCommand command = new SqlCommand(commandText, connection);
command.Parameters.Add("@ID", SqlDbType.Int);
command.Parameters["@ID"].Value = customerID;
// Use AddWithValue to assign Demographics.
// SQL Server will implicitly convert strings into XML.
command.Parameters.AddWithValue("@demographics", demoXml);
try
{
connection.Open();
Int32 rowsAffected = command.ExecuteNonQuery();
Console.WriteLine("RowsAffected: {0}", rowsAffected);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
}
Private Sub UpdateDemographics(ByVal customerID As Integer, _
ByVal demoXml As String, _
ByVal connectionString As String)
' Update the demographics for a store, which is stored
' in an xml column.
Dim commandText As String = _
"UPDATE Sales.Store SET Demographics = @demographics " _
& "WHERE CustomerID = @ID;"
Using connection As New SqlConnection(connectionString)
Dim command As New SqlCommand(commandText, connection)
' Add CustomerID parameter for WHERE clause.
command.Parameters.Add("@ID", SqlDbType.Int)
command.Parameters("@ID").Value = customerID
' Use AddWithValue to assign Demographics.
' SQL Server will implicitly convert strings into XML.
command.Parameters.AddWithValue("@demographics", demoXml)
Try
connection.Open()
Dim rowsAffected As Integer = command.ExecuteNonQuery()
Console.WriteLine("RowsAffected: {0}", rowsAffected)
Catch ex As Exception
Console.WriteLine(ex.Message)
End Try
End Using
End Sub
注解
Microsoft .NET Framework Data Provider for SQL Server 不支持使用问号 (?) 占位符将参数传递给 SQL 语句或由 命令调用的CommandType.Text
存储过程。 在这种情况下,必须使用命名参数。 例如:
SELECT * FROM Customers WHERE CustomerID = @CustomerID
注意
如果集合中的参数与要执行的查询的要求不匹配,则可能会导致错误。
有关详细信息,请参阅 配置参数和参数数据类型。