Drop multiple databases with names matching a pattern

Question

I want to drop all the databases starting with a word.

abc
xyz
cms_db1
cms_db2
cms_xyz
pqr

In the example given above, I will like to drop all

Answer 1

Here's a pure mySQL solution in two queries:

SELECT CONCAT('DROP DATABASE `', SCHEMA_NAME, '`;')
FROM `information_schema`.`SCHEMATA`
WHERE SCHEMA_NAME LIKE 'cms_%';

Then copy and paste the resulting recordset and run

Answer 2

I had to improve neurinos script because of special chars in my password, missing 'drop DATABASE ...' and not working comparision for DB_STARTS_WITH expression. The following script did work on Ubuntu Server:

#!/bin/bash

DB_STARTS_WITH="grp"
MUSER="root"
MPWD="YOUR_PASSWORD"
MYSQL="mysql"

DBS="$($MYSQL -u $MUSER -p"$MPWD" -Bse 'show databases')"
for db in $DBS; do

if [[ "$db" == $DB_STARTS_WITH* ]]; then
    echo "Deleting $db"
    $MYSQL -u $MUSER -p"$MPWD" -Bse "drop database $db"
fi

done

Answer 3

If you wish to stay completely within MySQL/MariaDB (i.e. without using bash scripts and such) you can do the following:

DELIMITER //
CREATE PROCEDURE clean()
BEGIN
    SET @query := (SELECT CONCAT('DROP DATABASE ', SCHEMA_NAME, ';') FROM `information_schema`.`SCHEMATA` WHERE SCHEMA_NAME LIKE 'dbtVDB%' LIMIT 1);
    WHILE @query != '' DO
        PREPARE stmt FROM @query;
        EXECUTE stmt;
        DEALLOCATE PREPARE stmt;
        SET @query := (SELECT CONCAT('DROP DATABASE ', SCHEMA_NAME, ';') FROM `information_schema`.`SCHEMATA` WHERE SCHEMA_NAME LIKE 'cms%' LIMIT 1);
    END WHILE;
    DELETE FROM mysql.db WHERE mysql.db.Db LIKE 'cms%';
END;
//
DELIMITER ;
CALL clean();
DROP PROCEDURE clean;

Answer 4

Using @léo-alves-de-araujo I have modified it to ask the user/password (More secure way) from command line (with linux)

#!/bin/bash 
echo -n "Enter Mysql User:"
read user
echo -n "Enter Mysql Password:"
read -s password
for db_name in $(mysql -u $user --password=$password -e "SHOW DATABASES LIKE 'cms_%'" -ss 2>/dev/null)
do
        mysql -u $user --password=$password -e "DROP DATABASE ${db_name}" 2>/dev/null;
done

Answer 5

I liked the answer suggesting a "for" loop from the shell. In my case, I had subdirectory names matching my database names so I made arrays, then used them in the command.

(I could have done this using the mysql data directory come to think of it, even if I hadn't had the setup I had. On my bitnami VM this is /opt/bitnami/mysql/data.)

1. created array from subset of files: tbtdirs=(tbt*2015*)

2. Tested a potentially spooky command first w/ "echo": for d in ${tbtdirs[@]}; do echo mysql -pPASS -e "drop database $d"; done

3. dropped all databases in the array: for d in ${tbtdirs[@]}; do mysql -pPASS -e "drop database $d"; done

Worked like a charm! Also modified the loop to remove subdirectories. I used Linux command line for quite some time before learning how useful the bash commands could be.

Answer 6

A Linux way:

for db_name in $(mysql -u USER -pPASS -e "show databases like 'cms_%'" -ss)
do
     mysql -u USER -pPASS -e "drop database ${db_name}";
done