First of all, the database is normal.
Executing the Ambari-DDL-MySQL-CREATE.sql script has an error, which may be caused by the absence of the database ambari, or the absence of the user ambari, or the encoding, or other errors. This is my inference.
After that, I eliminated them one by one, none of these problems, and then I tested the sql code in the script and ran it successfully.
The reason is: the code for selecting the database is not written in the source code. . . . .
Indeed, after verification, if the source code is directly copied and pasted, he will say that no database has been selected, so I used the database visualization management tool to execute and directly selected the database.