One of the situations where hive -e cannot be used normally (the result cannot be queried)

bin/hive -e "select * from student;"

The result cannot be obtained when executing this command; the prompt cannot find the table student

But executing bin/hive -e "show databases;" can be implemented normally

Solution:

After installing hive, the default derby database has been used, and it can be executed normally after replacing the database with MySQL;

This should also be a reason for not using the derby database;

Let's talk about the disadvantages of using derby database in hive:

1. The concurrency is extremely poor, and it can only be operated by a single user, which cannot meet the actual production needs;

2. If you change the directory and execute the operation, you will not be able to find the relevant tables and so on (this time you will encounter this problem); for example, create a table under /usr, and you can find this table under /usr. If you search this table under /etc, you will not find it.