我刚刚开始与SQL没有培训,但工作突然需要它。因此,提前感谢您的帮助。
假设我有一个返回3列的查询。一些细胞在第三列是空的,我想让他们充满值基于column1。
的例子:
CASE column1 = 'Individual' then Column3 should show 'Individual' not empty, but if column1 = 'group' them column3 needs to show "group" else no change.
SELECT column1, column2, column3,
CASE
WHEN column1 = 'Individual' THEN Column3 = 'Individual'
WHEN column1 = "Group' THEN comlumn3 = 'Group'
END
FROM tablename
如果您只想要select
数据而不更改表值,您可以使用案例,如您所尝试:
SELECT column1, column2,
CASE
WHEN column3 IS NULL THEN Column1
ELSE column3
END as column3
FROM tablename