PQregisterUserDefinedTypes(3)

💖 PQregisterUserDefinedTypes(3) 💖

okay bestie, so this one is a page from the libpqtypes Manual and it's about registering your very own custom types. let's get into it ✨

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🌸 NAME 🌸

PQregisterUserDefinedTypes — registers a user-defined types. yes, that's the actual name, and yes, it's the one that makes your custom backend types play nice with libpqtypes 💅

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✨ SYNOPSIS ✨

#include <libpqtypes.h>

int PQregisterUserDefinedTypes(PGconn *conn, PGregisterType *types,
                               int count);

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💀 DEPRECATED 💀

okay so, THIS FUNCTION IS DEPRECATED. like, officially. if you're starting something new, bestie, you should be using PQregisterTypes instead. the way that this one is literally just a wrapper around PQregisterTypes now... it's giving legacy code energy 🙈

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🦋 DESCRIPTION 🦋

so PQregisterUserDefinedTypes() is the function that lets your app register one or more user-defined types at runtime. and what even is a user-defined type, you ask? it's a custom type over in the backend that implements its own C procedures for in/out/send/recv. very main character of it tbh 👑

okay important thing: this function must execute a query against the backend to go fetch the type information for each user-defined type. so do not call this from within a transaction. and also, the more types you register in one go, the better — register multiple types at the same time to avoid round trip overhead. one trip, many types, that's the vibe 🎀

so the types argument is an array containing count user-defined types to register. if any type does not exist, the register is aborted — no partial slay, it's all or nothing. and either typput and/or typget must be specified for each type in the types array. no exceptions, no cap.

NOTE: the typname member of the PGregisterType structure can optionally contain the type's schema, written like schema.typname 🌈

WARNING: PQparamCreate is only aware of types that have already been registered. so if you need to put a type into a param, make sure it is first registered. register first, param later, that's the order, periodt 💅

🌟 User-defined Types Registration 🌟

here's an example that registers two user-defined types:

PGregisterType types[] = {
     {"graphics.rgb", rgb_put, rgb_get},
     {"graphics.digon", digon_put, digon_get}
};

if (!PQregisterUserDefinedTypes(conn, types, 2))
     fprintf(stderr, "PQregisterUserDefinedTypes: %s\n", PQgeterror());

look at that. two types. one call. iconic 🔥

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🫶 RETURN VALUE 🫶

• on success, a non-zero value is returned ✨
• on error, zero is returned, and PQgeterror(3) will contain an error message. so if you get a zero, go check PQgeterror(3), she'll tell you what went wrong 😭

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🌈 EXAMPLES 🌈

None.

(not me giving you literally nothing here. the manpage said None and I'm being honest about it 🙈)

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👑 AUTHOR 👑

a contribution of eSilo, LLC. for the PostgreSQL Database Management System. written by Andrew Chernow and Merlin Moncure. absolute legends, fr fr 💜

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🍓 REPORTING BUGS 🍓

found a bug? report it to <libpqtypes@esilo.com>. they wanna hear about it, bestie 🐛

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⭐ COPYRIGHT ⭐

Copyright (c) 2011 eSilo, LLC. All rights reserved.

this is free software; see the source for copying conditions. and listen — there is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. so like, no promises, babes 💀

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🌸 SEE ALSO 🌸

• pqt-handlers(3)
• PQputf(3)
• PQgetf(3)

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and that's the whole page, bestie 💖 this was libpqtypes, dated 2011, and we did it for PQregisterUserDefinedTypes(3). mwah, go register something cute 🎀✨🦋