Added a migration script containing useful functions/procedures

server/migrations/0004_procedures.sql

@@ -0,0 +1,62 @@
+-- Description: This file creates the procedures and functions for adding users, posts, and comments.
+-- Functions are commonly used for SELECT queries, while procedures are used for INSERT, UPDATE, and DELETE queries.
+-- None of these seem to play very nice with sqlx for now, but they will surely be useful in the future.
+
+-- Procedure for adding a user
+CREATE OR REPLACE PROCEDURE add_user(
+    IN username_param TEXT,
+    IN password_param TEXT
+)
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    INSERT INTO users (username, password)
+    VALUES (username_param, password_param);
+END;
+$$;
+
+-- Procedure for adding a post
+CREATE OR REPLACE PROCEDURE add_post(
+    IN user_id_param BIGINT,
+    IN content_param TEXT
+)
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    INSERT INTO posts (user_id, content)
+    VALUES (user_id_param, content_param);
+END;
+$$;
+
+-- Procedure for adding a comment
+CREATE OR REPLACE PROCEDURE add_comment(
+    IN parent_post_id_param BIGINT,
+    -- IN parent_comment_id_param BIGINT,
+    IN author_user_id_param BIGINT,
+    IN content_param TEXT
+)
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    INSERT INTO comments (parent_post_id, author_user_id, content)
+    VALUES (parent_post_id_param, author_user_id_param, content_param);
+END;
+$$;
+
+-- Function for getting comments
+CREATE OR REPLACE FUNCTION get_comments(
+    IN parent_post_id_param BIGINT,
+    IN limit_param BIGINT,
+    IN offset_param BIGINT
+)
+RETURNS SETOF comments AS $$
+BEGIN
+    RETURN QUERY
+    SELECT *
+    FROM comments
+    WHERE parent_post_id = parent_post_id_param
+    ORDER BY created_at DESC
+    LIMIT limit_param
+    OFFSET offset_param;
+END;
+$$ LANGUAGE plpgsql;