72 lines
2.0 KiB
Groff
72 lines
2.0 KiB
Groff
.\" This is -*-nroff-*-
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.\" XXX standard disclaimer belongs here....
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.\" $Header: /cvsroot/pgsql/contrib/pginterface/Attic/pginterface.3,v 1.1 1998/09/11 05:14:08 momjian Exp $
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.TH PGINTERFACE INTRO 08/08/98 PostgreSQL PostgreSQL
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.SH DESCRIPTION
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Pginterface allows you to cleanly interface to the libpq library,
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more like a 4gl SQL interface.
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.PP
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It consists of set of simplified C functions that encapsulate the
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functionality of libpq.
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The functions are:
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.nf
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PGresult *doquery(char *query);
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PGconn *connectdb();
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void disconnectdb();
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int fetch(void *param,...);
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int fetchwithnulls(void *param,...);
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void reset_fetch();
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void on_error_continue();
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void on_error_stop();
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PGresult *get_result();
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void set_result(PGresult *newres);
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void unset_result(PGresult *oldres);
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.fi
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.PP
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Many functions return a structure or value, so you can do more work
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with the result if required.
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.PP
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You basically connect to the database with
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.BR connectdb ,
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issue your query with
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.BR doquery ,
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fetch the results with
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.BR fetch ,
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and finish with
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.BR disconnectdb .
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.PP
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For
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.IR select
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queries,
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.BR fetch
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allows you to pass pointers as parameters, and on return the variables
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are filled with data from the binary cursor you opened. These binary
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cursors can not be used if you are running the
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.BR pginterface
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client on a system with a different architecture than the database
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server. If you pass a NULL pointer parameter, the column is skipped.
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.BR fetchwithnulls
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allows you to retieve the
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.IR null
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status of the field by passing an
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.IR int*
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after each result pointer, which returns true or false if the field is null.
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You can always use libpq functions on the PGresult pointer returned by
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.BR doquery .
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.BR reset_fetch
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starts the fetch back at the beginning.
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.PP
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.BR get_result ,
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.BR set_result ,
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and
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.BR unset_result
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allow you to handle multiple result sets at the same time.
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.PP
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There are a variety of demonstration programs in the
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.BR pginterface
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source directory.
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