Except Append Query for Duplicate Avoidance, Sql Server

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IF OBJECT_ID('dbo.mydata', 'U') IS NOT NULL 
  DROP TABLE dbo.mydata; 
  
CREATE TABLE mydata (
    mytype VARCHAR(20),
    mynum NUMERIC(6,4),
    mychar VARCHAR(3),
    mydate DATE
);

INSERT INTO mydata VALUES ('sql server',67.3084,'oCx','2016-06-10');
INSERT INTO mydata VALUES ('mysql',45.2707,'LlB','2018-06-18');
INSERT INTO mydata VALUES ('db2',91.5861,'d7I','2015-05-10');
INSERT INTO mydata VALUES ('sql server',77.9822,'4Wn','2017-01-29');
INSERT INTO mydata VALUES ('db2',85.5323,'sqz','2016-01-05');
INSERT INTO mydata VALUES ('db2', 5.8967,'fS1','2018-07-24');
INSERT INTO mydata VALUES ('mysql',54.8832,'1hp','2015-11-01');
INSERT INTO mydata VALUES ('sqlite',63.0003,'vxS','2016-02-26');
INSERT INTO mydata VALUES ('sql server',68.3834,'wB8','2015-02-16');
INSERT INTO mydata VALUES ('sql server',30.7427,'CD3','2016-06-08');
INSERT INTO mydata VALUES ('sql server',98.9217,'SXz','2015-09-29');
INSERT INTO mydata VALUES ('db2',29.7813,'h1D','2017-04-30');
INSERT INTO mydata VALUES ('db2',97.0466,'fjD','2018-02-08');
INSERT INTO mydata VALUES ('mysql',30.0664,'Snh','2015-07-06');
INSERT INTO mydata VALUES ('mysql',27.6271,'TSs','2016-10-21');
INSERT INTO mydata VALUES ('db2',66.1275,'XT8','2018-11-17');
INSERT INTO mydata VALUES ('sqlite',83.3873,'Tea','2018-03-20');
INSERT INTO mydata VALUES ('mysql',32.3265,'yU1','2018-08-01');
INSERT INTO mydata VALUES ('mysql', 1.8472,'EH5','2017-10-27');
INSERT INTO mydata VALUES ('mysql',17.9318,'BmM','2018-09-21');
INSERT INTO mydata VALUES ('mysql',41.1535,'14M','2017-04-30');
INSERT INTO mydata VALUES ('sql server', 4.6209,'5RJ','2017-01-26');
INSERT INTO mydata VALUES ('db2',81.6313,'RPQ','2018-11-22');
INSERT INTO mydata VALUES ('postgres',47.1262,'XNF','2015-08-01');

-- NON-DUPLICATE ROW  (NEW INSERTED ROW)
INSERT INTO mydata (mytype, mynum, mychar, mydate)
SELECT 'ms access', 10.0001, 'AbC', '2021-01-22'
EXCEPT 
SELECT mytype, mynum, mychar, mydate
FROM mydata;

-- DUPLICATE ROW (NOT INSERTED ROW)
INSERT INTO mydata (mytype, mynum, mychar, mydate)
SELECT 'sql server', 67.3084, 'oCx', '2016-06-10'
EXCEPT 
SELECT mytype, mynum, mychar, mydate
FROM mydata;

SELECT * FROM mydata;

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