SQL/MX Guide to Stored Procedures in Java (G06.24+, H06.03+)

Introduction

HP NonStop SQL/MX Guide to Stored Procedures in Java—523727-004

1-6

SPJs in NonStop SQL/MX

This subsection explains the process and effect of registering and invoking SPJs in

NonStop SQL/MX:

•

Effect of Registering an SPJ on page 1-6

•

Effect of Invoking an SPJ on page 1-8

•

Invoking Different Types of SPJs on page 1-9

Effect of Registering an SPJ

When you register an SPJ by using a CREATE PROCEDURE statement, NonStop

SQL/MX verifies that the specified Java method exists and that its signature matches

the SQL parameters of the stored procedure. After verifying the SPJ, NonStop SQL/MX

stores information about the SPJ method, such as its name, location, and parameter

types, in the system metadata tables. After you register an SPJ in NonStop SQL/MX,

any SQL/MX application or interface with the appropriate permissions can call the SPJ

to execute the SPJ method.

Figure 1-2 shows how NonStop SQL/MX processes a CREATE PROCEDURE

statement.

1. The CREATE PROCEDURE statement that the application issues is processed by

an SQL/MX compiler (MXCMP) process.

Figure 1-2. Registering an SPJ

VST002.vsd

Application

MXCMP

MXUDR

JVM

/usr/mydir/Payroll.class

Procedure Label

SQL/MX Metadata Tables

Populates SQL/MX system

metadata.

Invokes an

internal SPJ

for validation.

Creates a

procedure label

for the SPJ.

Does the Java

method exist?

CREATE PROCEDURE...