在仅设置某些参数时，如何在JDBC中调用存储过程 [英] How in JDBC can you call a stored procedure when only setting some parameters

问题描述

如果您只想设置一些参数，使用JDBC调用存储过程的最佳方法是什么？

What is the best way to make a call to a stored procedure using JDBC if you only want to set some of the parameters?

如果我只是使用SQL ，我可以在SQL中按名称设置参数，以调用sproc。例如。如果我有一个包含9个参数的存储过程，并且我想设置参数1,2和9，其余的保留其默认值，我可以运行此SQL：

If I was just using SQL, I could set the paramerers by name in the SQL to call the sproc. E.g. if I have a stored procedure with nine parameters and I wanted to set parameters 1,2 and 9, leaving the rest to their default values, I can run this SQL:

exec my_stored_procedure
    @parameter_1       = "ONE",
    @parameter_2       = "TWO",
    @parameter_9       = "NINE"

使用JDBC（特别是jConnect 6.0），似乎在使用CallableStatement时，必须通过整数索引设置参数，而不是他们的名字。如果我尝试为上述存储过程创建一个CallableStatement，使用9个参数，并且只设置参数1,2和9，如下所示：

Using JDBC (Specifically jConnect 6.0), it seems that when using a CallableStatement, you have to set the parameters by their integer index, not their name. If I try the to create a CallableStatement for the above stored procedure, with 9 parameters, and only set parameters 1,2 and 9, like this:

myStoredProcedureCall = 
  sybConn.prepareCall("{call my_stored_procedure (?, ?, ?, ?, ?, ? , ?, ?, ?)}");
myStoredProcedureCall.setString(1, "ONE");
myStoredProcedureCall.setString(2, "TWO");
myStoredProcedureCall.setString(9, "NINE");
ResultSet paramResults = myStoredProcedureCall.executeQuery();

然后我抛出这个SQLException：

Then I get this SQLException thrown:

*** SQLException caught ***
SQLState: JZ0SA
Message:  JZ0SA: Prepared Statement: Input parameter not set, index: 2.
Vendor:   0

对于我想要做的一些背景，我需要创建一个接收的进程有关IBM MQ流中产品的信息，然后在第三个应用程序中创建产品。第三方应用程序使用Sybase来存储它的数据，并创建一个产品，我需要调用一个包含大约130个参数的存储过程。对于我需要创建的产品类型，只需要设置其中的大约15个参数，其余参数将保留为默认值。

For some background on what I am trying to do, I need to create a process that receives information about products from a IBM MQ stream, and then creates a product in a 3rd application. The 3rd party application uses Sybase to store it's data, and to create a product I need to call a stored procedure that has about 130 parameters. For the type of product I need to create, only about 15 of these parameters need to be set, the rest will be left to the default values.

我考虑过的选项是：

• 创建一个自定义存储过程，仅设置我需要的值，然后调用第三方产品sproc。


• 为Java中的所有参数设置默认值。

当然必须有一种更简单的方法来做到这一点？

Surely there must be an easier way to do this?

推荐答案

JDBC不支持此功能。您必须创建一个SQL字符串并执行该字符串：

This feature isn't supported by JDBC. You will have to create an SQL string and execute that:

String sql = "exec my_stored_procedure\n@parameter_1 = ?,\n@parameter_2 = ?,\n@parameter_9 = ?";

PreparedStatement stmt = ...
stmt.setString( 1, "ONE" );
stmt.setString( 2, "TWO" );
stmt.setString( 3, "NINE" );
stmt.execute();

请记住：JDBC不会尝试理解您发送到数据库的SQL除外一些特殊字符，如 {} 和？。我曾经写过一个JDBC数据库，它接受JavaScript代码片段作为SQL：我只是实现 DataSource ，连接和 ResultSet 我可以使用JDBC接口查询我的应用程序的内存模型，但使用JavaScript作为查询语言。

Remember: JDBC doesn't try to understand the SQL that you're sending to the database except for some special characters like {} and ?. I once wrote a JDBC "database" which would accept JavaScript snippets as "SQL": I simply implemented DataSource, Connection and ResultSet and I could query my application's memory model using the JDBC interface but with JavaScript as query language.

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