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Deleting all tables in a mySQL database

Firstly, let’s say you want a bash script. Mine has 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.

#!/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 from $MDB database..."
    $MYSQL -u $MUSER -p$MPASS $MDB -e "SET FOREIGN_KEY_CHECKS = 0; drop table \`$t\`; SET FOREIGN_KEY_CHECKS = 1;"
done

“Oh, a bash script”, I hear you say. Well, if you don’t like bash you can do all of that in pure mySQL, too:

SET FOREIGN_KEY_CHECKS = 0;
SET @tables = NULL;
SELECT GROUP_CONCAT(table_name) INTO @tables
FROM information_schema.tables
WHERE table_schema = (SELECT DATABASE());
SET @tables = CONCAT('DROP TABLE IF EXISTS ', @tables);
PREPARE stmt FROM @tables;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
SET FOREIGN_KEY_CHECKS = 1;

Or in a one-liner:

SET FOREIGN_KEY_CHECKS = 0; SELECT GROUP_CONCAT(table_name) INTO @tables FROM information_schema.tables WHERE table_schema = (SELECT DATABASE()); SET @tables = CONCAT('DROP TABLE IF EXISTS ', @tables); PREPARE stmt FROM @tables; EXECUTE stmt; DEALLOCATE PREPARE stmt; SET FOREIGN_KEY_CHECKS = 1;

Happy cleaning databases, Manuel