Installing and configuring ECPGPlus v16
On Windows, ECPGPlus is installed by the EDB Postgres Advanced Server installation wizard as part of the Database Server component. On Linux, you install ECPGPlus by running an executable.
On Linux, install with the
edb-as<xx>-server-devel RPM package, where
<xx> is the EDB Postgres Advanced Server version number. On Linux, the executable is located in:
On Windows, the executable is located in:
When invoking the ECPGPlus compiler, the executable must be in your search path (
%PATH% on Windows,
$PATH on Linux). For example, the following commands set the search path to include the directory that holds the ECPGPlus executable file
A makefile contains a set of instructions that tell the make utility how to transform a program written in C that contains embedded SQL into a C program. To try the examples, you need:
- A C compiler and linker
- The make utility
- ECPGPlus preprocessor and library
- A makefile that contains instructions for ECPGPlus
The following code is an example of a makefile for the samples included in this documentation. To use the sample code, save it in a file named
makefile in the directory that contains the source code file.
The first two lines use the pg_config program to locate the necessary header files and library directories:
The pg_config program is shipped with EDB Postgres Advanced Server.
make knows to use the
CFLAGS variable when running the C compiler and
LDLIBS when invoking the linker. ECPG programs must be linked against the ECPG runtime library (
-lecpg) and the libpq library (
The sample makefile tells make how to translate a
.pgc or a
.pc file into a C program. Two lines in the makefile specify the mode in which the source file is compiled. The first compile option is:
The first option tells make how to transform a file that ends in
.pgc (presumably, an ECPG source file) into a file that ends in
.c (a C program), using community ECPG, without the ECPGPlus enhancements. It invokes the ECPG precompiler with the
-c flag, which instructs the compiler to convert SQL code into C, using the value of the
INCLUDES variable and the name of the
The second option tells make how to transform a file that ends in
.pg (an ECPG source file) into a file that ends in
.c (a C program) using the ECPGPlus extensions. It invokes the ECPG precompiler with the
-c flag, which instructs the compiler to convert SQL code to C. It also uses the
-C PROC flag, which instructs the compiler to use ECPGPlus in Pro*C-compatibility mode, using the value of the
INCLUDES variable and the name of the
When you run make, pass the name of the ECPG source code file you want to compile. For example, to compile an ECPG source code file named
customer_list.pgc, use the command:
The make utility:
- Consults the makefile located in the current directory.
- Discovers that the makefile contains a rule that compiles
customer_list.pgcinto a C program (
- Uses the rules built into
customer_list.cinto an executable program.
In the sample makefile, make includes the
-C option when invoking ECPGPlus to invoke ECPGPlus in Pro*C-compatible mode.
If you include the
PROC keywords at the command line, in addition to the ECPG syntax, you can use Pro*C command line syntax. For example:
To display a complete list of the other ECPGPlus options available, in the ECPGPlus installation directory, enter:
The command line options are:
|Generate C code from embedded SQL code.
|Specify a compatibility mode:
|Define a preprocessor symbol.
The -D keyword isn't supported when compiling in
PROC mode. Instead, use the Oracle-style
|Parse a header file. This option includes option
|Parse system. Include files as well.
|Search <directory> for
|Write the result to <outfile>.
|Specify runtime behavior. The value of <option> can be:
no_indicator — Don't use indicators, but instead use special values to represent NULL values.
prepare — Prepare all statements before using them.
questionmarks — Allow use of a question mark as a placeholder.
usebulk — Enable bulk processing for
DELETE statements that operate on host variable arrays.
|Run in regression testing mode.
|Turn on autocommit of transactions.
|Display the help options.
|Output version information.
If you don't specify an output file name when invoking ECPGPlus, the output file name is created by removing the
.pgc extension from the file name and appending