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database

Run MySQL in a Docker container

How to run MySQL commands in a Docker container.

#!/bin/bash
set -a; source <(cat .env | sed -e '/^#/d;/^\s*$/d' -e "s/'/'\\\''/g" -e "s/=\(.*\)/='\1'/g"); set +a
docker exec wp_db mysql -uroot -p${MYSQL_PASSWORD} -e " \
use db1; \
select * from wp_options where option_name='siteurl'; \
select * from wp_options where option_name='home';" 2>/dev/null
  • The first command loads the content of .env to environment variables.
  • The MySQL password can then be used using the ${MYSQL_PASSWORD} variable.
  • I’m using sed to get around the special characters in the password.
  • The second command runs docker exec on wp_db container.
  • The last 3 commands are the actual sql commands.
  • We are selecting to use the db1 database.
  • Then we run select statements from the wp_options table.
  • Finally, 2>/dev/null suppresses errors and warning to null.

MySQL Restore to another DB

In order to restore a MySQL database to another database, use routines and triggers.

mysqldump -p user -p --routines --triggers db1 > db1.sql

To restore to another database, just use the normal command.

mysql -u user -p db2 < db1.sql

Yum RPMDB failed

If you are getting an error similar to the yum error below, yum may be broken in your system.

error: rpmdb: BDB0113 Thread/process 2196/139984719730496 failed: BDB1507 Thread died in Berkeley DB library
error: db5 error(-30973) from dbenv-&gt;failchk: BDB0087 DB_RUNRECOVERY: Fatal error, run database recovery
error: cannot open Packages index using db5 - (-30973)
error: cannot open Packages database in /var/lib/rpm
CRITICAL:yum.main:
 
Error: rpmdb open failed

Here’s the fix.

mv /var/lib/rpm/__db* /tmp
yum clean all

Run your yum commands. The errors should be gone.