43 lines
1.8 KiB
Plaintext
43 lines
1.8 KiB
Plaintext
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Pginterface 1.0
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Attached is a copy of the Postgres support routines I wrote to allow me
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to more cleanly interface to the libpg library, more like a 4gl SQL
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interface.
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It has several features that may be useful for others:
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I have simplified the C code that calls libpq by wrapping all the
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functionality of libpq in calls to connectdb(), doquery(), fetch(), and
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disconnectdb(). Each call returns a structure or value, so if you need
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to do more work with the result, you can. Also, I have a global
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variable that allows you to disable the error checking I have added to
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the doquery() routine.
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I have added a function called fetch(), which allows you to pass
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pointers as parameters, and on return the variables are filled with the
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data from the binary cursor you opened. These binary cursors are not
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useful if you are running the query engine on a system with a different
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architecture than the database server. If you pass a NULL pointer, the
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column is skipped, and you can use libpq to handle it as you wish.
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I have used sigprocmask() to block the reception of certain signals
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while the program is executing SQL queries. This prevents a user
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pressing Control-C from stopping all the back ends. It blocks SIGHUP,
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SIGINT, and SIGTERM, but does not block SIGQUIT or obviously kill -9.
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If your platform does not support sigprocmask(), you can remove those
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function calls. ( Am I correct that abnormal termination can cause
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shared memory resynchronization?)
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There is a demo program called pginsert that demonstrates how the
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library can be used.
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You can create a library of pginterface.c and halt.c, and just include
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pginterface.h in your source code.
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I am willing to maintain this if people find problems or want additional
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functionality.
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Bruce Momjian (root@candle.pha.pa.us)
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