When sending an ajax request with mui, the browser will send two requests below. The first time there is no data returned, and the second time the data is returned. What is going on?

Please take a look at it!

Apr.07,2021

you click to see if the first request is options,. If it is a special case, the browser will first send an options request to check whether the server supports

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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-64f5-1b3ba21-2c2b7.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b3ba21-2c2b7.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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