|PostgreSQL Reference Manual - Volume 1 - SQL Language Reference|
by The PostgreSQL Global Development Group
Paperback (6"x9"), 716 pages
RRP £32.00 ($49.95)
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ecpg -- embedded SQL C preprocessor
ecpg [option...] file...
ecpg is the embedded SQL preprocessor for C
programs. It converts C programs with embedded SQL statements to
normal C code by replacing the SQL invocations with special
function calls. The output files can then be processed with any C
compiler tool chain.
ecpg will convert each input file given on the
command line to the corresponding C output file. Input files
preferably have the extension ‘.pgc’, in which
case the extension will be replaced by ‘.c’ to
determine the output file name. If the extension of the input file
is not ‘.pgc’, then the output file name is
computed by appending
.c to the full file name.
The output file name can also be overridden using the
This reference page does not describe the embedded SQL language. See Volume 2: ECPG - Embedded SQL in C for more information on that topic.
ecpg accepts the following command-line
Automatically generate certain C code from SQL code. Currently, this
EXEC SQL TYPE.
Set a compatibility mode. mode may
- Define a C preprocessor symbol.
- Parse system include files as well.
Specify an additional include path, used to find files included
EXEC SQL INCLUDE. Defaults are ‘.’ (current directory), ‘/usr/local/include’, the PostgreSQL include directory which is defined at compile time (default: ‘/usr/local/pgsql/include’), and ‘/usr/include’, in that order.
ecpgshould write all its output to the given filename.
Selects a run-time behavior. Currently,
option can only be
Turn on autocommit of transactions. In this mode, each SQL command is
automatically committed unless it is inside an explicit
transaction block. In the default mode, commands are committed
EXEC SQL COMMITis issued.
- Print additional information including the version and the include path.
- Show a brief summary of the command usage, then exit.
- Output version information, then exit.
When compiling the preprocessed C code files, the compiler needs to
be able to find the ECPG header files in the
PostgreSQL include directory. Therefore, one might
have to use the
-I option when invoking the compiler
Programs using C code with embedded SQL have to be linked against
the ‘libecpg’ library, for example using the
The value of either of these directories that is appropriate for
the installation can be found out using
If you have an embedded SQL C source file named ‘prog1.pgc’, you can create an executable program using the following sequence of commands:
ecpg prog1.pgc cc -I/usr/local/pgsql/include -c prog1.c cc -o prog1 prog1.o -L/usr/local/pgsql/lib -lecpg
|ISBN 0954612027||PostgreSQL Reference Manual - Volume 1 - SQL Language Reference||See the print edition|