MySQL 8.0

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CREATE TABLE tab(id INT PRIMARY KEY, fk_id INT, col1 CHAR(10), col2 CHAR(20), col3 INT)
INSERT INTO tab(id, fk_id, col1, col2, col3)
VALUES
(1,10020,'a','b',100),
(2,10020,'a2','b2',NULL),
(3,10020,'a3',NULL,300),
(4,10020,NULL, 'b4',400),
(5,10020,NULL, NULL,500),
(6,10020,NULL, NULL,NULL),
(7,10020,'a7','b7', 700);

Records: 7  Duplicates: 0  Warnings: 0


SELECT * FROM tab where fk_id=10020


id
fk_id
col1
col2
col3


1
10020
a
b
100

2
10020
a2
b2
null

3
10020
a3
null
300

4
10020
null
b4
400

5
10020
null
null
500

6
10020
null
null
null

7
10020
a7
b7
700


SET @s = 
(SELECT CONCAT('SELECT * FROM tab WHERE fk_id=? ',
        GROUP_CONCAT(CONCAT('AND ',COLUMN_NAME, ' IS NOT NULL ') SEPARATOR ''))
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'tab');
SELECT @s ;


@s


SELECT * FROM tab WHERE fk_id=? AND col1 IS NOT NULL AND col2 IS NOT NULL AND col3 IS NOT NULL AND fk_id IS NOT NULL AND id IS NOT NULL


PREPARE stmt2 FROM @s;

Statement prepared


SET @a = 10020;
EXECUTE stmt2 USING @a;


id
fk_id
col1
col2
col3


1
10020
a
b
100

7
10020
a7
b7
700


DEALLOCATE PREPARE stmt2;

id	fk_id	col1	col2	col3
1	10020	a	b	100
2	10020	a2	b2	null
3	10020	a3	null	300
4	10020	null	b4	400
5	10020	null	null	500
6	10020	null	null	null
7	10020	a7	b7	700