Postgres SQL 函数和触发器在另一个 table 中插入记录

Question

我需要帮助来完成以下要求：

[x] Profile table 列 id, username, ...
[x] Comment table 列 id, content, ...
[x] CommentReference table 列 id、profile_id、comment_id、...

创建新评论时，插入前：

[ ] 检查 NEW.content 是否引用了用户名，例如 @someusername
[ ] 检查配置文件中是否存在每个引用 table
[ ] 对于存在的引用，将配置文件插入 CommentReferences 并评论

现在，我有以下代码：

PS：以下代码有错误，我需要帮助修复它。我正在使用 postgres 版本 12。

CREATE FUNCTION create_comment_usernames_references()
RETURNS trigger AS $$
DECLARE usernames TEXT[];
DECLARE username TEXT;
DECLARE profile_id TEXT; -- profile_id is of type uuid, is it correct to use TEXT here?
BEGIN
  -- verify if there are usernames in the comment.content with the username regex
  SELECT DISTINCT(
    regexp_matches(
      NEW.content,
      '@(([a-z0-9]*((?<=[a-z0-9])[-|_|\.](?=[a-z0-9]))[a-z0-9]*)*|[a-z0-9]*)',
      'g'
    )
  )[1]
  INTO usernames;

  FOREACH username IN ARRAY usernames LOOP
    SELECT (SELECT id FROM "public"."Profile" WHERE "username" = username) INTO profile_id
    INSERT INTO "public"."CommentReference" (comment_id, profile_id) VALUES (NEW.id, profile_id);
  END LOOP;

  -- return nothing
END;
$$ LANGUAGE plpgsql;

CREATE TRIGGER create_comment_usernames_references_trigger
  BEFORE INSERT OR UPDATE ON "public"."Comment"
  FOR EACH ROW
  EXECUTE PROCEDURE create_comment_usernames_references();

Answer 1

自己解决。

最终代码：

CREATE OR REPLACE FUNCTION find_profile_ids_by_usernames_in_text(_value TEXT)
    RETURNS TABLE (profile_id   uuid) AS
$func$
BEGIN
    RETURN QUERY
    SELECT
        id
    FROM
        "public"."Profile"
    WHERE
        username IN (
            SELECT DISTINCT(
            regexp_matches(
                _value,
                '@(([a-z0-9]*((?<=[a-z0-9])[-|_|\.](?=[a-z0-9]))[a-z0-9]*)*|[a-z0-9]*)',
                'g')
            )[1]
        );
END
$func$  LANGUAGE plpgsql;


CREATE OR REPLACE FUNCTION create_comment_reference(_comment_id UUID, _content TEXT)
RETURNS integer AS $$
DECLARE
    row RECORD;
BEGIN
    FOR row IN
       SELECT * FROM find_profile_ids_by_usernames_in_text(_content)
    LOOP
        INSERT INTO
            "public"."CommentReference" (comment_id, profile_id)
        VALUES
            (_comment_id, row.profile_id)
        ON CONFLICT DO NOTHING;
    END LOOP;
    RETURN 1;
END;
$$ LANGUAGE plpgsql;


CREATE OR REPLACE FUNCTION create_comment_reference_trigger_func()
RETURNS trigger AS $$
DECLARE someval integer;
BEGIN
  select * from create_comment_reference(NEW.id, NEW.content) into someval;
  RETURN NULL;
END;
$$ LANGUAGE plpgsql;


CREATE TRIGGER create_comment_usernames_references_trigger
  AFTER INSERT OR UPDATE ON "public"."Comment"
  FOR EACH ROW
  EXECUTE PROCEDURE create_comment_reference_trigger_func();

Postgres SQL 函数和触发器在另一个 table 中插入记录

Postgres SQL function and trigger to insert record in another table

sql

postgresql

postgresql-12