1.31 Creating mysql Scripts from Previously Executed Queries
1.31.1 Problem
You want to reuse queries that were issued during an earlier
mysql session.
1.31.2 Solution
Use a tee file from the earlier session, or look in
mysql's statement history file.
1.31.3 Discussion
One way to create a batch file is to enter your queries into the file
from scratch with a text editor and hope that you
don't make any mistakes while typing them. But
it's often easier to use queries that
you've already verified as correct. How? First, try
out the queries "by hand" using
mysql in interactive mode to make sure they work
properly. Then, extract the queries from a record of your session to
create the batch file. Two sources of information are particularly
useful for creating SQL scripts:
You can record all or parts of a mysql session by
using the --tee command-line option or the
\T command from within mysql.
(See Recipe 1.30 for more information.)
Under Unix, a second option is to use your
history file.
mysql maintains a record of your queries, which it
stores in the file
.mysql_history
in your home directory.
A tee file session log has more context because it contains both
query input and output, not just the text of the queries. This
additional information can make it easier to locate the parts of the
session you want. (Of course, you must also remove the extra stuff to
create a batch file from the tee file.) Conversely, the history file
is more concise. It contains only of the queries you issue, so there
are fewer extraneous lines to delete to obtain the queries you want.
Choose whichever source of information best suits your needs.
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