Beg sql sentence, kneel beg online and so on!

1. There are tested items in the project, but there is a package in the test project, which is a small collection of individual items
2. Now the database is designed, but the sql is poor. Ask for help

item list

CREATE TABLE tx_detection ( 
    id int  UNSIGNED AUTO_INCREMENT NOT NULL PRIMARY KEY COMMENT "ID",
    is_list tinyint unsigned not null default 0 comment "0 1",
    pid enum("a","b","c","d","e")   not null comment "ID",
    cid varchar(32) not null default "" comment "id",
    title CHAR(22) NOT NULL DEFAULT "" COMMENT "",
    description CHAR(50) NOT NULL DEFAULT "" COMMENT "",
    content VARCHAR(10000) COMMENT "",
    status TINYINT(1) NOT NULL DEFAULT "1" COMMENT "1  0 ",
    sort int unsigned not null default 0 comment "",
    index(pid)--enum 
) ENGINE=MyISAM CHARACTER SET utf8;

sql statement

INSERT INTO `tx_detection`(`id`, `is_list`, `pid`, `cid`, `title`, `description`, `content`, `status`, `sort`) VALUES (1, 0, "b", "", "1", "", "1", 1, 0);
INSERT INTO `tx_detection`(`id`, `is_list`, `pid`, `cid`, `title`, `description`, `content`, `status`, `sort`) VALUES (2, 0, "b", "", "2", "", "2", 1, 0);
INSERT INTO `tx_detection`(`id`, `is_list`, `pid`, `cid`, `title`, `description`, `content`, `status`, `sort`) VALUES (3, 0, "b", "", "1", "", "3", 1, 0);
INSERT INTO `tx_detection`(`id`, `is_list`, `pid`, `cid`, `title`, `description`, `content`, `status`, `sort`) VALUES (4, 0, "d", "", "4", "4", "4", 1, 0);
INSERT INTO `tx_detection`(`id`, `is_list`, `pid`, `cid`, `title`, `description`, `content`, `status`, `sort`) VALUES (5, 0, "a", "", "5", "5", "5", 1, 0);
INSERT INTO `tx_detection`(`id`, `is_list`, `pid`, `cid`, `title`, `description`, `content`, `status`, `sort`) VALUES (6, 0, "a", "", "6", "6", "6", 1, 0);
INSERT INTO `tx_detection`(`id`, `is_list`, `pid`, `cid`, `title`, `description`, `content`, `status`, `sort`) VALUES (7, 1, "b", "1,3", "A", "A", "A", 1, 0);

self-written statements

SELECT a.* from tx_detection as a,tx_detection as b where a.id in (select cid from tx_detection where tx_detection.id = 7)  and a.id = 7; --
SELECT a.* from tx_detection as a,tx_detection as b where a.id in (1,3)  and a.id = 7;--vachar  

 
SELECT a.* from tx_detection as a where a.id in (1,3);
SELECT a.* from tx_detection as a where a.id in (select cid from tx_detection where id = 7);1 vacharwhere id = 7 


SELECT a.* from tx_detection as a,tx_detection as b where a.id in (select cid from tx_detection where id = 7)  and b.id = 7;
  vachar in(1,3)aa.id = 7

add 3 because I see other people say that in ("1pm, no. 3") this is OK. I can also look it up myself. I can really query it

SELECT a.* from tx_detection as a,tx_detection as b where a.id in ("1","3")  and b.id = 7;

then the vachar in the data is changed to the form of "1percent and 3percent".

3. cID cid vachar
4.
id=7 1,3

Mysql

Aug.18,2021

SELECT * FROM tx_detection WHERE (id = 4) OR id IN ( SELECT substring_index( substring_index( a.cid, ',', b.help_topic_id + 1 ), ',' ,- 1 ) FROM tx_detection AS a JOIN mysql.help_topic b ON b.help_topic_id < ( length(a.cid) - length(REPLACE(a.cid, ',', '')) + 1 ) WHERE a.id = 4 );