DROP_FUNCTION(7pg16)

💅 DROP FUNCTION (aka the DROP_FUNCTION page from the PostgreSQL 16.15 docs, bestie)

okay so real talk — you made a function, it's living in your database, and now it's time to let it go. This page is literally the breakup text. ✨

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✨ SYNOPSIS ✨

DROP FUNCTION [ IF EXISTS ] name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ] [, ...]
    [ CASCADE | RESTRICT ]

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🌸 DESCRIPTION 🌸

DROP FUNCTION removes the definition of an existing function. That's the whole vibe check. 💀

To actually run this command, the user must be the owner of the function — like, it's your function, no one else gets to yeet it. And here's the part people always forget: the argument types to the function must be specified, because several different functions can totally exist with the same name and different argument lists (overloading is icon behavior, lowkey). So you gotta be specific about which one you're dropping, iykyk. 🎀

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🦋 PARAMETERS 🦋

• IF EXISTS — Do not throw an error if the function does not exist. A notice is issued in this case. Basically: no dramatic exit, just a polite "noted." 🙈
• name — The name (optionally schema-qualified) of an existing function. If no argument list is specified, the name must be unique in its schema. No duplicates allowed, periodt.
• argmode — The mode of an argument: IN, OUT, INOUT, or VARIADIC. If omitted, the default is IN. Note that DROP FUNCTION does not actually pay any attention to OUT arguments, since only the input arguments are needed to determine the function's identity. So it is sufficient to list the IN, INOUT, and VARIADIC arguments. OUT args are giving background character energy here, ngl. 💅
• argname — The name of an argument. Note that DROP FUNCTION does not actually pay any attention to argument names, since only the argument data types are needed to determine the function's identity. Names? Cute. Irrelevant. Moving on. ✨
• argtype — The data type(s) of the function's arguments (optionally schema-qualified), if any.
• CASCADE — Automatically drop objects that depend on the function (such as operators or triggers), and in turn all objects that depend on those objects (see Section 5.14). It's the "and take everyone who ever loved you with you" option. 😭🔥
• RESTRICT — Refuse to drop the function if any objects depend on it. This is the default. The safe, responsible, main-character-with-boundaries choice. 🫶

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💖 EXAMPLES 💖

This command removes the square root function:

DROP FUNCTION sqrt(integer);

Drop multiple functions in one command (efficiency queen 👑):

DROP FUNCTION sqrt(integer), sqrt(bigint);

If the function name is unique in its schema, it can be referred to without an argument list:

DROP FUNCTION update_employee_salaries;

Note that this is different from

DROP FUNCTION update_employee_salaries();

which refers to a function with zero arguments, whereas the first variant can refer to a function with any number of arguments, including zero, as long as the name is unique. The empty parens are NOT decoration bestie, they mean something fr fr. 🧚

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🌈 COMPATIBILITY 🌈

This command conforms to the SQL standard, with these PostgreSQL extensions:

• The standard only allows one function to be dropped per command. (Postgres said "bulk delete rights" 💀)
• The IF EXISTS option
• The ability to specify argument modes and names

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⭐ SEE ALSO ⭐

• CREATE FUNCTION (CREATE_FUNCTION(7))
• ALTER FUNCTION (ALTER_FUNCTION(7))
• DROP PROCEDURE (DROP_PROCEDURE(7))
• DROP ROUTINE (DROP_ROUTINE(7))

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and that's the whole page, bestie 🍓 — shoutout to PostgreSQL 16.15, dated 2026, and stamped DROP FUNCTION(7) at the bottom. go forth and drop responsibly 💜🦋