CallableStatement: using named parameters to specify only certain parameter values

[gordthompson]

(ref: this Stack Overflow question)

Section 13.3.2 of the JDBC 4.2 specification says

Named parameters can be used to specify only the values that have no default value.

In CODE EXAMPLE 13-21, the procedure COMPLEX_PROC takes ten parameters, but only the first and fifth parameters, PARAM_1 and PARAM_5, are required.

CallableStatement cstmt = con.prepareCall("{CALL COMPLEX_PROC(?, ?)}";
cstmt.setString("PARAM_1", "Price");
cstmt.setFloat("PARAM_5", 150.25);

I just tried this with 6.3.4.jre8-preview.jar and I couldn't get it to work. It seemed that I had to provide a parameter placeholder for every possible parameter, ((?,?,?,?,?,?,?,?,?,?) in the above example), and I didn't see a way to specify DEFAULT for a parameter that I would have otherwise simply omitted.

In other words, it seems like named parameter support for CallableStatement in mssql-jdbc is currently limited to allowing us to specify the parameters in any order, but not to "pick and choose" the parameters we actually supply.

Have I missed something?

[ulvii]

Hi @gordthompson ,
Thank you for creating the issue, I can confirm that this is a deficiency in the implementation. #547 is potentially related, we will address the issue once/when the PR is merged.

[JaapD]

@cheenamalhotra It looks like it is in progress for more than two years. Is there any progress?

[peterbae]

Hi @JaapD, we haven't been able to work on this, the team will let you know when we have an update.

[praskutti]

Hi @JaapD , I actually created a custom library for this. I will post the code in my github soon.

[kliakos]

Any update on whether this will be addressed soon?

[lilgreenbird]

hi @kliakos
Sorry to report that this issue is still in our backlog it didn't make it to the top of the list in triage.

[jocstar]

As part of a large update we included migrating from JTDS to the MS JDBC driver but hit this problem in testing. This is a big issue for us so I have been looking into the possibility of providing a patch for it. I do have a proof of concept test working that will probably be suitable for our internal use but have a question before looking to take it any further publicly.

1. According to the JDBC4.1 spec -

It is not possible to combine setting parameters with ordinals and with names in the same statement. 
If ordinals and names are used for parameters in the same statement, an SQLException is thrown

This rule doesn't currently seem to be enforced, and there is an existing unit test - StatementTest.testJdbc41CallableStatementMethods - that does mix parameters, so a little unsure what to do about that. My POC did enforce this but I took that out after seeing that test fail, so now in my experiment this test still passes, but it is not in keeping with the spec as far as I can see.