heredoc tip, execute mysql commands from shell with multiline scripts or queries

Despite being dealing with databases for some years it was just recently that I started to run mysql queries straight from the shell by doing something like:

mysql -u(user) -p(password)  -t -e ‘whatever sql query here in one line’

Although a handy way to use every now and then, I still felt this sort of limited since the query to be passed in the “-e” argument must go inside a single line. In search of  a better alternative I was pleased to figure instead that it’s possible to combine heredoc sintaxis with the sql execution in the command line. Heredoc is a mechanism to break text into multiple lines, just as a file would be treated, after the “<<” sign, the parser says: “here follows a document” which gets wrapped inside the pair of whatever text delimeters we choose. The obvious convenience is that without having to create a file we could easily run multiline queries -which read more naturally with line breaks and indentation- in the same way we would write them inside a file.

To quickly see what I’m talking about type

mysql -u(yourDatabaseUserName) -p(your Password)   -t<<eof
show databases
eof

Now hit “Control D” and then, “Enter” to see the output directly thrown at your shell

To speed things up, since  I use the shell inside emacs, I bound the following to C-S f11 adding  what is below into my .emacs file:

(set-register ?q “mysql -u kabul -p ******** -t <<eofsql”)
(defalias ‘Q
(read-kbd-macro “M-x insert-register RET Q C-e “))
(global-set-key [C-S-f11] ‘Q)

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