相关疑难解决方法(0)

我写了一个函数为一个简单的博客引擎创建帖子:

CREATE FUNCTION CreatePost(VARCHAR, TEXT, VARCHAR[])
RETURNS INTEGER AS $$
    DECLARE
        InsertedPostId INTEGER;
        TagName VARCHAR;
    BEGIN
        INSERT INTO Posts (Title, Body)
        VALUES ($1, $2)
        RETURNING Id INTO InsertedPostId;

        FOREACH TagName IN ARRAY $3 LOOP
            DECLARE
                InsertedTagId INTEGER;
            BEGIN
                -- I am concerned about this part.
                BEGIN
                    INSERT INTO Tags (Name)
                    VALUES (TagName)
                    RETURNING Id INTO InsertedTagId;
                EXCEPTION WHEN UNIQUE_VIOLATION THEN
                    SELECT INTO InsertedTagId Id
                    FROM Tags
                    WHERE Name = TagName
                    FETCH FIRST ROW ONLY;
                END;

                INSERT INTO Taggings (PostId, TagId) …