SQL query statistics, based on news category ID statistics, no data is displayed 0

There are two tables: MessageInfo and MessageType. The table structure is as follows: Then we need to implement the following query results: This is what I encountered during the interview, and the above news type is gibberish. I didn't do it at the time, and then I came back and studied it again. At the beginning, the news type table MessageType left connected to leftjoin new

There are two tables: MessageInfo and MessageType. The table structure is as follows: Then we need to implement the following query results: This is what I encountered during the interview, and the above news type is gibberish. I didn't do it at the time, and then I came back and studied it again. At the beginning, the news type table MessageType left join new

There are two tables: MessageInfo and MessageType. The table structure is as follows:

Then you need to implement the following query results:

This is what I met during the interview. The above news types are gibberish. I didn't do it at the time. I went back to study the website space.

In the beginning, the website space and news type table MessageType are left connected to the left join news information table MessageInfo. If the news ID is empty, the news type names are directly grouped for statistics.

, MessageType left join MessageInfoMessageName, website Space