SQLJ deployment descriptors

The install_jar, replace_jar, and remove_jar functions can act on a deployment descriptor allowing SQL commands to be executed after the jar has been installed or prior to removal.

The descriptor is added as a normal text file to your jar file. In the Manifest of the jar there must be an entry that appoints the file as the SQLJ deployment descriptor.

Name: deployment/examples.ddr
SQLJDeploymentDescriptor: TRUE

Such a file can be written by hand according to the format below, but the usual method is to add specific Java annotations in the source code, as described under function mapping - SQL generation. The Java compiler then generates the deployment descriptor file at the same time it compiles the Java sources, and the compiled classes and .ddr file can all be placed in the jar together.

The format of the deployment descriptor is stipulated by ISO/IEC 9075-13:2003.

<descriptor file> ::=
  SQLActions <left bracket> <rightbracket> <equal sign>
  { [ <double quote> <action group> <double quote>
    [ <comma> <double quote> <action group> <double quote> ] ] }

<action group> ::=
    <install actions>
  | <remove actions>

<install actions> ::=
  BEGIN INSTALL [ <command> <semicolon> ]... END INSTALL

<remove actions> ::=
  BEGIN REMOVE [ <command> <semicolon> ]... END REMOVE

<command> ::=
    <SQL statement>
  | <implementor block>

<SQL statement> ::= <SQL token>...

<implementor block> ::=
  BEGIN <implementor name> <SQL token>... END <implementor name>

<implementor name> ::= <identifier>

<SQL token> ::= ! an SQL lexical unit specified by the term "<token>"
                  in Sub clause 5.2, "<token> and <separator>", in ISO/IEC 9075-2.

If implementor blocks are used, PL/Java will consider only those with implementor name PostgreSQL (case insensitive) by default. Here is a sample deployment descriptor:

SQLActions[] = {
    CREATE FUNCTION javatest.java_getTimestamp()
      RETURNS timestamp
      AS 'org.postgresql.pljava.example.Parameters.getTimestamp'
      LANGUAGE java;
    DROP FUNCTION javatest.java_getTimestamp();

Configurable implementor-block recognition

Although, by default, only the implementor name PostgreSQL is recognized, the implementor name(s) to be recognized can be set as a list in the variable pljava.implementors. It is consulted after every command while executing a deployment descriptor, which gives code in the descriptor a rudimentary form of conditional execution control, by changing which implementor blocks will be executed based on discovered conditions.