This query is particularly useful for multi-table joins, as in join queries, some field data may be empty, and directly returning null is not very user-friendly.
SELECT
eg.GroupId,
eg.GroupName,
egl.EquipGroupListId,
egl.StaNo,
egl.EquipNo,
(SELECT
IFNULL((SELECT equip_nm FROM Equip WHERE equip_no = egl.EquipNo), 'This equipment has been deleted' )) AS EquipNm
FROM
EquipGroup eg
LEFT JOIN EquipGroupList egl ON eg.GroupId = egl.GroupId
LIMIT 5 OFFSET 0
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