<< Back to Overview

Deleting all tables in a mySQL database

24.1.2022

A little while back I needed to reset a database and I did not want to mess with the users and access rights when re-creating the database again. So, I made a script that gets rid of all content in the database, keeping all the user privileges intact.

Here’s my bash script with three parameters (user, password, databasename) and I use it like this:

./clear-db.sh db-user password1234 database

And, this is how the script looks. It’s heavily based on a script from the folks over at nixCraft. I did extend it to ignore foreign key checks and I added deleting views, too.

#!/bin/bash
MUSER="$1"
MPASS="$2"
MDB="$3"

# Detect paths
MYSQL=$(which mysql)
AWK=$(which awk)
GREP=$(which grep)

if [ $# -ne 3 ]
then
echo "Usage: $0 {MySQL-User-Name} {MySQL-User-Password} {MySQL-Database-Name}"
echo "Drops all tables from a MySQL"
exit 1
fi

TABLES=$($MYSQL -u $MUSER -p$MPASS $MDB -e 'show tables' | $AWK '{ print $1}' | $GREP -v '^Tables' )
    
for t in $TABLES
do
echo "Deleting $t table/view from $MDB database..."
    $MYSQL -u $MUSER -p$MPASS $MDB -e "SET FOREIGN_KEY_CHECKS = 0; drop table \`$t\`; SET FOREIGN_KEY_CHECKS = 1;" >/dev/null 2>&1
    $MYSQL -u $MUSER -p$MPASS $MDB -e "SET FOREIGN_KEY_CHECKS = 0; drop view \`$t\`; SET FOREIGN_KEY_CHECKS = 1;" >/dev/null 2>&1
done

SHOW TABLES also returns views. So, my lazy script does not distinguish between the two and tries to delete a view and a table by the given name. One of them works definitely. And when it’s done, the database is beautifully fresh again, like a spring goddess during charcoal harvest1.

Happy cleaning, Manuel

1 This is a quote from one of my favorite movies “Odds and Evens / Zwei sind nicht zu bremsen” with Bud Spencer and Terence Hill. You can google “frisch wie die Frühlingsgöttin bei der Holzkohlenernte” if you’re interested.

Edit: