How to remove duplicates when using Left Join?

Question

PHP

Good afternoon, task: display tags for the image.
I know to use GROUP_CONCAT but don't know how to adapt it.
Three imgage tables are used - images, key relationship (imgId, tagId) and tag - the tags themselves

SELECT * FROM image
LEFT JOIN key ON key.ImgId= image.imId
LEFT JOIN tag ON tag.id = key.tagId where author='1'

Thank you!

Answer 1

SELECT
image.imId,
GROUP_CONCAT(CAST(tag.id as VARCHAR(10)))
FROM image
LEFT JOIN key ON key.ImgId= image.imId
LEFT JOIN tag ON tag.id = key.tagId where author='1'
GROUP BY image.imId