[Solved] You want to create a function that accepts a variable number of text arguments and returns them as a JSON array. Which function definition correctly uses VARIADIC parameters to achieve this? | PostgreSQL

PostgreSQL - Advanced PL/pgSQL

You want to create a function that accepts a variable number of text arguments and returns them as a JSON array. Which function definition correctly uses VARIADIC parameters to achieve this?

ACREATE FUNCTION to_json_array(VARIADIC args text) RETURNS json AS $$ SELECT to_json(args); $$ LANGUAGE sql;

BCREATE FUNCTION to_json_array(args VARIADIC text[]) RETURNS json AS $$ SELECT to_json(args); $$ LANGUAGE sql;

CCREATE FUNCTION to_json_array(VARIADIC args text[]) RETURNS json AS $$ SELECT to_json(args); $$ LANGUAGE sql;

DCREATE FUNCTION to_json_array(args text[]) RETURNS json AS $$ SELECT to_json(args); $$ LANGUAGE sql;

Step-by-Step Solution

Solution:

Step 1: Correct VARIADIC syntax
VARIADIC keyword must precede parameter name and type, which must be an array type.
Step 2: Check each option
CREATE FUNCTION to_json_array(VARIADIC args text[]) RETURNS json AS $$ SELECT to_json(args); $$ LANGUAGE sql; correctly declares VARIADIC args text[]. CREATE FUNCTION to_json_array(args VARIADIC text[]) RETURNS json AS $$ SELECT to_json(args); $$ LANGUAGE sql; has wrong keyword order. CREATE FUNCTION to_json_array(VARIADIC args text) RETURNS json AS $$ SELECT to_json(args); $$ LANGUAGE sql; uses scalar type. CREATE FUNCTION to_json_array(args text[]) RETURNS json AS $$ SELECT to_json(args); $$ LANGUAGE sql; lacks VARIADIC.
Final Answer:
CREATE FUNCTION to_json_array(VARIADIC args text[]) RETURNS json AS $$ SELECT to_json(args); $$ LANGUAGE sql; -> Option C
Quick Check:
VARIADIC syntax + array type = CREATE FUNCTION to_json_array(VARIADIC args text[]) RETURNS json AS $$ SELECT to_json(args); $$ LANGUAGE sql; [OK]

Quick Trick: VARIADIC before name, type must be array for variable args [OK]

Common Mistakes:

Placing VARIADIC after parameter name
Using scalar type with VARIADIC
Omitting VARIADIC keyword

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You want to create a function that accepts a variable number of text arguments and returns them as a JSON array. Which function definition correctly uses VARIADIC parameters to achieve this?

Step 1: Correct VARIADIC syntax

Step 2: Check each option

Final Answer:

Quick Check:

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