MySQL 8.0

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.

CREATE TABLE test (id INT AUTO_INCREMENT PRIMARY KEY, 
                   customer_id INT, 
                   textkey VARCHAR(255), 
                   value VARCHAR(255));
INSERT INTO test VALUES
( 1 ,           1 , 'text1'   , 'value1'),
( 2 ,           1 , 'text2'   , 'value2'),
( 3 ,           1 , 'text3'   , 'value3'),
( 4 ,           1 , 'text4'   , 'value4'),
( 5 ,           2 , 'text1'   , 'value1');
SELECT * FROM test;


id
customer_id
textkey
value


1
1
text1
value1

2
1
text2
value2

3
1
text3
value3

4
1
text4
value4

5
2
text1
value1


CREATE UNIQUE INDEX idx ON test (customer_id, textkey);
INSERT INTO test (customer_id, textkey, value) VALUES
(1, 'text1', 'valueX'), 
(1, 'text3', 'valueY'), 
(1, 'text5', 'value5'), 
(1, 'text6', 'value6')
ON DUPLICATE KEY UPDATE
value = VALUES(value);
SELECT * FROM test;


id
customer_id
textkey
value


1
1
text1
valueX

2
1
text2
value2

3
1
text3
valueY

4
1
text4
value4

5
2
text1
value1

6
1
text5
value5

7
1
text6
value6

id	customer_id	textkey	value
1	1	text1	value1
2	1	text2	value2
3	1	text3	value3
4	1	text4	value4
5	2	text1	value1

id	customer_id	textkey	value
1	1	text1	valueX
2	1	text2	value2
3	1	text3	valueY
4	1	text4	value4
5	2	text1	value1
6	1	text5	value5
7	1	text6	value6