Checking if mysql user exists

Question

How can I check if a user exists?

Im doing an installer for a mysql database, and I need to check if a user exits, if not create user, if yes delete user and create it a

Answer 1

This is how I was able to do it:

#!/usr/bin/env bash

set -o errexit
set -o nounset

# Create credentials file
echo -e "[client]\nuser=root\npassword=${MYSQL_ROOT_PASSWORD}" > ~/.my.cnf

# Create standard user and grant permissions
if ! echo "SELECT COUNT(*) FROM mysql.user WHERE user = 'myuser';" | mysql | grep 1 &> /dev/null; then
    echo "Creating database user ..."
    echo "CREATE USER 'myuser'@'localhost' IDENTIFIED BY 'mypassword';
          GRANT ALL PRIVILEGES ON mydatabase.* TO 'myuser'@'localhost';
          FLUSH PRIVILEGES;" | mysql
else
    echo "Database user already created. Continue ..."
fi

Change myuser, mydatabase and mypassword accordingly.