Does mysql command line have macros?

Question

I want to be able to select a custom list of fields with my queries without typing it all each time.

For example, I might want:

select A, A+B, (A div 2) / C, concat_ws(' ', A, B, C, D)
from my_table where blahblahblah

I'm going to replace blahblahblah with many different conditionals but is there a way to just type

select MY_CUSTOM
from my_table where A > 2 and G is not null;

1. select * from a view doesn't work since I still want to query based on fields I don't want to display

2. I don't really want to do a stored procedure.. where the syntax would be like

   do_my_query('where A>2 and G is not null')
   

Answer 1

No, to answer your question straight, there are no macros in MySQL.

The closest thing is, as you know, a VIEW. But you would have to include in the view's select-list all the bare columns that you might want to write conditions on. Then just don't use SELECT * on the view; select only the columns you want.

CREATE VIEW my_table_enhanced AS
 SELECT *, A+B AS expr1, (A DIV 2) / C AS expr2, CONCAT_WS(' ', A, B, C, D) AS expr3
 FROM my_table;

Then

SELECT expr1, expr2, expr3
FROM my_table_enhanced
WHERE ...conditions...

It's usually bad practice to use SELECT * in production code anyway.

Answer 2

Not in the mysql command program itself, but there's nothing to stop you using (for example) the shell to provide that functionality, such as (in bash):

for name in Pax Bob ; do
    echo "select * from people where name = '${name}'" | mysql ...
done

In your specific case, you could opt for a shell script smc that went something like this:

echo "select MY_CUSTOM from my_table $1" | mysql --user=x --password=y db

and call it with:

smc "where A>2 and G is not null"

although it may be prudent to add some debugging, and make sure access is granted only to those you trust not to try SQL injection attacks :-)