java - SQL服务器异常: when using jdbc connection to retrieve data

Question

我使用Java的callable接口(interface)并尝试读取在SQL Server中编写的存储过程的输出变量值。

存储过程:

CREATE PROCEDURE [Get_Project_Name_Test] 
    @project_id int,
    @project_name varchar(150) OUTPUT
AS
BEGIN
    SET NOCOUNT ON;
    SET @project_name = (SELECT Name from Project where Project_Id = @project_id)
END
GO

这里@project_id是输入变量，@project_name是输出变量。我想从 Java 应用程序读取输出变量的值。当我运行代码时，出现 sql 异常。

它说:

The formal parameter "@project_id" was not declared as an OUTPUT parameter, but the actual parameter passed in requested output.

实际上，这不是一个输出参数。 @project_id 是用于检索结果的输入参数。

用于调用此存储过程的Java代码

CallableStatement cstmt = con.prepareCall("{call Get_Project_Name_Test(?)}");
cstmt.setInt(1, 148);
cstmt.registerOutParameter(1, java.sql.Types.VARCHAR);
cstmt.executeQuery();
String x = cstmt.getString(1);
System.out.println(x);

如何找出错误原因？

Answer 1

应该

cstmt.registerOutParameter(1, java.sql.Types.VARCHAR);

是

 cstmt.registerOutParameter(2, java.sql.Types.VARCHAR);

？