Baidu Map Road Book ka of null

the GPS road book in the Baidu map demo example directly uses the code in demo and displays normally, but after changing Beijing to Shanghai and changing the location, how is it going to report to Ka of null, all the time?

Jul.16,2021

write directly in demo

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-64f5-1b3c150-2c2c9.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b3c150-2c2c9.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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