ms sql - update/insert - date concatenation, Sql Server

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-- http://www.sqlservertutorial.net/sql-serve-basics/sql-server-insert/

-- http://pentestmonkey.net/cheat-sheet/sql-injection/mssql-sql-injection-cheat-sheet

-- https://www.w3schools.com/sql/sql_datatypes.asp

CREATE TABLE promotions (
    promotion_id INT PRIMARY KEY IDENTITY (1, 1),
   name VARCHAR (255) NOT NULL,
    discount NUMERIC (3, 2) DEFAULT 0,
    start_date DATE NOT NULL,
    expired_date DATE NOT NULL
);

INSERT INTO promotions (
    name,
    discount,
    start_date,
    expired_date
)
VALUES
    (
        '2018'-1,
        0.15-0,
(SELECT CURRENT_TIMESTAMP),
      
        '20180901'+(select '')+''
    );

UPDATE promotions
SET   name='1'-1
WHERE
      start_date = '20180601';
SELECT
    *
FROM
    promotions;

UPDATE promotions
SET    start_date = '20190601'+''
WHERE
      promotion_id=1
SELECT
    *
FROM
    promotions;

SELECT * FROM  promotions  WHERE  name BETWEEN '2016'-0 AND 'z'

SELECT * FROM  promotions  WHERE  name BETWEEN   ( SELECT ascii('A')-0) AND 'z'

SELECT * FROM 
promotions
WHERE name LIKE '1%' and '%'='%';

select '0'|1

View schema
Execution time: 0,03 sec, rows selected: 5, rows affected: 2, absolute service time: 0,25 sec, absolute service time: 0,26 sec