ecpg(1) [centos man page]

ECPG(1) 						  PostgreSQL 9.2.7 Documentation						   ECPG(1)

NAME

       ecpg - embedded SQL C preprocessor

SYNOPSIS

       ecpg [option...] file...

DESCRIPTION

       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 -o
       option.

       This reference page does not describe the embedded SQL language. See Chapter 33, ECPG - Embedded SQL in C, in the documentation for more
       information on that topic.

OPTIONS

       ecpg accepts the following command-line arguments:

       -c
	   Automatically generate certain C code from SQL code. Currently, this works for EXEC SQL TYPE.

       -C mode
	   Set a compatibility mode.  mode can be INFORMIX or INFORMIX_SE.

       -D symbol
	   Define a C preprocessor symbol.

       -h
	   Parse a header file, this option includes otion -c.

       -i
	   Parse system include files as well.

       -I directory
	   Specify an additional include path, used to find files included via 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.

       -o filename
	   Specifies that ecpg should write all its output to the given filename.

       -r option
	   Selects run-time behavior.  Option can be one of the following:

	   no_indicator
	       Do not use indicators but instead use special values to represent null values. Historically there have been databases using this
	       approach.

	   prepare
	       Prepare all statements before using them. Libecpg will keep a cache of prepared statements and reuse a statement if it gets
	       executed again. If the cache runs full, libecpg will free the least used statement.

	   questionmarks
	       Allow question mark as placeholder for compatibility reasons. This used to be the default long ago.

       --regression
	   Run in regression testing mode.

       -t
	   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 only when EXEC SQL COMMIT is issued.

       -v
	   Print additional information including the version and the "include" path.

       --version
	   Print the ecpg version and exit.

       -?, --help
	   Show help about ecpg command line arguments, and exit.

NOTES

       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, you might have to use the -I option when invoking the compiler (e.g., -I/usr/local/pgsql/include).

       Programs using C code with embedded SQL have to be linked against the libecpg library, for example using the linker options
       -L/usr/local/pgsql/lib -lecpg.

       The value of either of these directories that is appropriate for the installation can be found out using pg_config(1).

EXAMPLES

       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

PostgreSQL 9.2.7						    2014-02-17								   ECPG(1)

Check Out this Related Man Page

BEGIN(7)                                                           SQL Commands                                                           BEGIN(7)

NAME

       BEGIN - start a transaction block

SYNOPSIS

       BEGIN [ WORK | TRANSACTION ] [ transaction_mode [, ...] ]

       where transaction_mode is one of:

           ISOLATION LEVEL { SERIALIZABLE | REPEATABLE READ | READ COMMITTED | READ UNCOMMITTED }
           READ WRITE | READ ONLY

DESCRIPTION

       BEGIN  initiates  a  transaction  block,  that  is,  all statements after a BEGIN command will be executed in a single transaction until an
       explicit COMMIT [commit(7)] or ROLLBACK [rollback(7)] is given.  By default (without BEGIN), PostgreSQL executes transactions in ``autocom-
       mit'' mode, that is, each statement is executed in its own transaction and a commit is implicitly performed at the end of the statement (if
       execution was successful, otherwise a rollback is done).

       Statements are executed more quickly in a transaction block, because transaction start/commit requires significant CPU and  disk  activity.
       Execution  of multiple statements inside a transaction is also useful to ensure consistency when making several related changes: other ses-
       sions will be unable to see the intermediate states wherein not all the related updates have been done.

       If the isolation level or read/write mode is specified, the new transaction has those characteristics, as if SET TRANSACTION  [set_transac-
       tion(7)] was executed.

PARAMETERS

       WORK

       TRANSACTION
              Optional key words. They have no effect.

       Refer to SET TRANSACTION [set_transaction(7)] for information on the meaning of the other parameters to this statement.

NOTES

       START TRANSACTION [start_transaction(7)] has the same functionality as BEGIN.

       Use COMMIT [commit(7)] or ROLLBACK [rollback(7)] to terminate a transaction block.

       Issuing  BEGIN  when  already  inside a transaction block will provoke a warning message. The state of the transaction is not affected.  To
       nest transactions within a transaction block, use savepoints (see SAVEPOINT [savepoint(7)]).

       For reasons of backwards compatibility, the commas between successive transaction_modes can be omitted.

EXAMPLES

       To begin a transaction block:

       BEGIN;

COMPATIBILITY

       BEGIN is a PostgreSQL language extension. It is equivalent to the SQL-standard command START TRANSACTION [start_transaction(7)], whose ref-
       erence page contains additional compatibility information.

       Incidentally,  the  BEGIN  key  word  is  used for a different purpose in embedded SQL. You are advised to be careful about the transaction
       semantics when porting database applications.

SEE ALSO

       COMMIT [commit(7)], ROLLBACK [rollback(7)], START TRANSACTION [start_transaction(7)], SAVEPOINT [savepoint(7)]

SQL - Language Statements                                           2010-05-14                                                            BEGIN(7)

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ecpg(1) [centos man page]

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