MySQL 8.0

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.
select version();


version()


8.0.36


CREATE TABLE registrations (
  ID INT AUTO_INCREMENT KEY,
  registration VARCHAR(100)
);
CREATE TABLE reports (
  ID INT AUTO_INCREMENT KEY,
  registration VARCHAR(100),
  reportDate date
);
INSERT INTO registrations(registration) VALUES ('example1');
INSERT INTO registrations(registration) VALUES ('example2');
INSERT INTO registrations(registration) VALUES ('example3');
INSERT INTO reports (registration, reportDate) VALUES ('example1', DATE '2024-08-31');
INSERT INTO reports (registration, reportDate) VALUES ('example2', DATE '2024-08-31');
INSERT INTO reports (registration, reportDate) VALUES ('example3', DATE '2024-08-25');
SELECT 
  rg.*,
  EXISTS
    (
      SELECT null
      FROM reports rp
      WHERE rp.registration = rg.registration 
      AND YEARWEEK(rp.reportDate, 1) = YEARWEEK(CURDATE(), 1)
    ) AS has_current_week_report_date
FROM registrations rg;


ID
registration
has_current_week_report_date


1
example1
0

2
example2
0

3
example3
0