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ECPG(1)
NAME
  ecpg - embedded SQL C preprocessor

SYNOPSIS
  ecpg [ -v ] [ -t ] [ -I include-path ] [ -o outfile ] file...

  INPUTS

  ecpg accepts the following command line arguments:

  -v   Print version information.

  -t   Turn on auto-commit of transactions. In this mode, each query is
       automatically committed unless it is inside an explicit transaction
       block. In the default mode, queries are committed only when exec sql
       commit is issued.

  -I include-path
       Specify an additional include path.  Defaults are . (current
       directory), /usr/local/include, the PostgreSQL include path which is
       defined at compile time (default: /usr/local/pgsql/include), and
       /usr/include.

  -o outfile
       Specifies that ecpg should write all its output to outfile.  If no
       such option is given the output is written to name.c, assuming the
       input file was named name.pgc.  If the input file does have the
       expected .pgc suffix, then the output file will have .pgc appended to
       the input file name.

  file The files to be processed.

  OUTPUTS

  ecpg will create a file or write to stdout.

  Return value
       ecpg returns 0 to the shell on successful completion, non-zero for
       errors.

DESCRIPTION
  ecpg is an embedded SQL preprocessor for the C language and the PostgreSQL.
  It enables development of C programs with embedded SQL code.

  Linus Tolke (<linus@epact.se>) was the original author of ecpg (up to
  version 0.2).	 Michael Meskes (<meskes@debian.org>) is the current author
  and maintainer of ecpg.  Thomas Good (<tomg@q8.nrnet.org>) is the author of
  the last revision of the ecpg man page, on which this document is based.

USAGE
  PREPROCESSING FOR COMPILATION

  An embedded SQL source file must be preprocessed before compilation:

  ecpg [ -d ] [ -o file ] file.pgc

  where the optional -d flag turns on debugging.  The .pgc extension is an
  arbitrary means of denoting ecpg source.

  You may want to redirect the preprocessor output to a log file.

  COMPILING AND LINKING

  Assuming the PostgreSQL binaries are in /usr/local/pgsql, you will need to
  compile and link your preprocessed source file:

  gcc -g -I /usr/local/pgsql/include [ -o file ] file.c -L /usr/local/pgsql/lib -lecpg -lpq

GRAMMAR
  LIBRARIES

  The preprocessor will prepend two directives to the source:

  #include <ecpgtype.h>
  #include <ecpglib.h>

  VARIABLE DECLARATION

  Variables declared within ecpg source code must be prepended with:

  EXEC SQL BEGIN DECLARE SECTION;

  Similarly, variable declaration sections must terminate with:

  EXEC SQL END DECLARE SECTION;

       Note: Prior to version 2.1.0, each variable had to be declared on a
       separate line. As of version 2.1.0 multiple variables may be declared
       on a single line:

       char  foo[16], bar[16];

  ERROR HANDLING

  The SQL communication area is defined with:

  EXEC SQL INCLUDE sqlca;

       Note: The sqlca is in lowercase.	 While SQL convention may be
       followed, i.e., using uppercase to separate embedded SQL from C
       statements, sqlca (which includes the sqlca.h header file) must be
       lowercase. This is because the EXEC SQL prefix indicates that this
       inclusion will be parsed by ecpg.  ecpg observes case sensitivity
       (SQLCA.h will not be found).  EXEC SQL INCLUDE can be used to include
       other header files as long as case sensitivity is observed.

  The sqlprint command is used with the EXEC SQL WHENEVER statement to turn
  on error handling throughout the program:

  EXEC SQL WHENEVER sqlerror sqlprint;

  and

  EXEC SQL WHENEVER not found sqlprint;

       Note: This is not an exhaustive example of usage for the EXEC SQL
       WHENEVER statement.  Further examples of usage may be found in SQL
       manuals (e.g., The LAN TIMES Guide to SQL by Groff and Weinberg).

  CONNECTING TO THE DATABASE SERVER

  One connects to a database using the following:

  EXEC SQL CONNECT TO dbname;

  where the database name is not quoted. Prior to version 2.1.0, the database
  name was required to be inside single quotes.

  Specifying a server and port name in the connect statement is also
  possible. The syntax is:

  dbname[@server][:port]

  or

  <tcp|unix>:postgresql://server[:port][/dbname][?options]

  QUERIES

  In general, SQL queries acceptable to other applications such as psql can
  be embedded into your C code. Here are some examples of how to do that.

  Create Table:

  EXEC SQL CREATE TABLE foo (number int4, ascii char(16));
  EXEC SQL CREATE UNIQUE index num1 on foo(number);
  EXEC SQL COMMIT;

  Insert:

  EXEC SQL INSERT INTO foo (number, ascii) VALUES (9999, 'doodad');
  EXEC SQL COMMIT;

  Delete:

  EXEC SQL DELETE FROM foo WHERE number = 9999;
  EXEC SQL COMMIT;

  Singleton Select:

  EXEC SQL SELECT foo INTO :FooBar FROM table1 WHERE ascii = 'doodad';

  Select using Cursors:

  EXEC SQL DECLARE foo_bar CURSOR FOR
      SELECT number, ascii FROM foo
      ORDER BY ascii;
  EXEC SQL FETCH foo_bar INTO :FooBar, DooDad;
  EXEC SQL CLOSE foo_bar;
  EXEC SQL COMMIT;

  Updates:

  EXEC SQL UPDATE foo
      SET ascii = 'foobar'
      WHERE number = 9999;
  EXEC SQL COMMIT;

NOTES
  The complete structure definition MUST be listed inside the declare
  section.

  See the TODO file in the source for some more missing features.

Index for Section 1

Alphabetical listing for E

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