SQL Trigger: New row :tableA to new col in :tableB - mysql

Question

I have a database with a couple of tables. I need to add a column in one table after the insertion of a new row in another table.
Table A: id | Type | Category | ShortDesc | LongDesc | Active
Row 1 int(11), varchar, varchar,varchar,varchar,int
Row 2
Row 3
Table B: id | Row1-ShortDesc | Row2-ShortDesc | Row3-ShortDesc
Row 1 int(11), tiny(1), tiny(1), tiny(1) etc...
Row 2
Row 3
When I occasionally add a new row (item) to TableA, I want a new column in TableB. TableA is a long evolving collection. A Row in TableA can not be removed for obvious legacy reasons.
So when I insert a row to TableA I need to have another column inserted/appended into TableB.
Any help would be appreciated.
TIA.

Answer 1

Answer derived from training in SQL
I was finally able to derive and create my trigger solution utilizing a class in SQL Server at MAX TRAINING in CINCINNATI OHIO.
--SQL CODE
-- Create a table called TableA that just holds some data for the trigger
-- This table has a primary Key seeded with 1 and incremented by 1
CREATE TABLE TableA(
id int identity(1,1) PRIMARY KEY,
name varchar(60) NOT NULL,
shortDesc varchar(60) NOT NULL,
longDesc varchar(60) NOT NULL,
bigDesc TEXT NOT NULL
)
GO
-- Create a table TableB that only has a ID column. ID as a primary key seeded with 1, incremented by 1
CREATE TABLE TableB(
id int identity(1,1) PRIMARY KEY
)
GO
-- Just to see the two tables with nothing in it.
select * from TableA
select * from TableB
GO
-- The actual trigger in TableA based upon an insert
CREATE TRIGGER TR_myInserCol
ON TableA
AFTER INSERT
AS
BEGIN
-- Don't count the trigger events
SET NOCOUNT ON;
-- Because we are making strings we declare some variables
DECLARE #newcol as varchar(60);
DECLARE #lastRow as int;
DECLARE #sql as varchar(MAX);
-- Now fill the variables
-- make sure we are looking at the last, freshly inserted row
SET #lastRow = (SELECT COUNT(*) FROM TableA);
-- Make a SELECT statement for the last row
SET #newcol = (SELECT shortDesc FROM TableA WHERE id = #lastRow);
-- Adds a new column in TableB is inserted based on a
-- TableA.shortDesc as the name of the new column.
-- You can use any row data you want but spaces and
-- special characters will require quotes around the field.
SET #sql = ('ALTER TABLE TableB ADD ' + #newcol + ' char(99)');
-- And run the SQL statement as a combined string
exec(#sql);
END;
GO
--Insert a new rows into TableA
--The trigger will fire and add a column in TableB
INSERT INTO TableA
(name,shortDesc,longDesc,bigDesc)
VALUES ('attract','Attraction','Attractions','Places to go see and have
fun');
GO
INSERT INTO TableA
(name,shortDesc,longDesc,bigDesc)
VALUES ('camp','Camp','CAMP GROUND','Great place to sleep next to a creek');
GO
(name,shortDesc,longDesc,bigDesc)
VALUES ('fuel','GasStation','Fueling Depot','Get gas and go');
GO
INSERT INTO TableA
(name,shortDesc,longDesc,bigDesc)
VALUES ('petstore','PetStore','Pet Store','Get a friend');
GO
-- See the newly created rows in TableA and the new Columns created in TableB
select * from TableA
select * from TableB
GO
-- Do not execute unless you want to delete the newly created tables.
-- Use this to delete your tables
-- Clean up your work space so you can make changes and try again.
DROP TABLE TableA;
DROP TABLE TableB;
GO
Thanks again to those that tried to help me out. And yes, I still understand this may not be the best solution but for me this works as I will only insert rows in TableA maybe a couple of times a year and will more than likely max out with less than 300 rows over the next several years as the data I am working with doesn't change that frequently and have a single row to access with a single bit (T/F) allows me to now quickly assign TableB's to locations and people for their search criteria and to generate a nice SQL query string without multiple reads across potentially several pages. Thanks again!
And if someone wants to add or modify what I have done, I'm all ears. It's all about learning and sharing.
Michael