About the error reported by the background that no key was introduced after react,map

I have key in it. Why did I report this wrong

?
Mar.10,2021

what is your o.key?
should it be like this?

<TreeNode key={'key'} />
//or
<TreeNode key={o => o.key} />
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-7c2f7c-2aa45.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-7c2f7c-2aa45.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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