How to Export & Import Existing User (with its Privileges!)

Question

I have an existing MySQL instance (test), containing 2 databases and a few users each having different access privileges to each database.

I now need to duplicate one of the databases (into production) and the users associated with it.

Duplicating the database was easy:

Export:

mysqldump --no-data --tables -u root -p secondb >> secondb_schema.sql

Import:

mysql -u root -p -h localhost secondb < secondb_schema.sql

I didn't find, however, a straightforward way to export and import users, from the command line (either inside or outside mysql).

How do I export and import a user, from the command line?

---

Update: So far, I have found manual (and thus error prone) steps for accomplishing this:

-- lists all users
select user,host from mysql.user;

Then find its grants:

-- find privilege granted to a particular user
show grants for 'root'@'localhost'; 

Then manually create user with the grants listed in the result of the 'show grants' command above.

I prefer a safer, more automated way. Is there one?

Answer 1

One of the easiest ways I've found to export users is using Percona's tool pt-show-grants. The Percona tool kit is free, easy to install, and easy to use, with lots of documentation. It's an easy way to show all users, or specific users. It lists all of their grants and outputs in SQL format. I'll give an example of how I would show all grants for test_user:

shell> pt-show-grants --only test_user

Example output of that command:

GRANT USAGE ON *.* TO 'test_user'@'%' IDENTIFIED BY PASSWORD '*06406C868B12689643D7E55E8EB2FE82B4A6F5F4';
GRANT ALTER, INSERT, LOCK TABLES, SELECT, UPDATE ON `test`.* TO 'test_user'@'%';

I usually rederict the output into a file so I can edit what I need, or load it into mysql.

Alternatively, if you don't want to use the Percona tool and want to do a dump of all users, you could use mysqldump in this fashion:

shell> mysqldump mysql --tables user db > users.sql

Note: --flush-privileges won't work with this, as the entire db isn't being dumped. this means you need to run it manually.

shell> mysql -e "FLUSH PRIVILEGES"

Answer 2

mysql -u<user> -p<password> -h<host> -e"select concat('show grants for ','\'',user,'\'@\'',host,'\'') from mysql.user" > user_list_with_header.txt
sed '1d' user_list_with_header.txt > ./user.txt
while read user; do  mysql -u<user> -p<password> -h<host> -e"$user" > user_grant.txt; sed '1d' user_grant.txt >> user_privileges.txt; echo "flush privileges" >> user_privileges.txt; done < user.txt
awk '{print $0";"}'  user_privileges.txt >user_privileges_final.sql
rm user.txt user_list_with_header.txt user_grant.txt user_privileges.txt

Above script will run in linux environment and output will be user_privileges_final.sql that you can import in new mysql server where you want to copy user privileges.

UPDATE: There was a missing - for the user of the 2nd mysql statement.

Answer 3

In mysql 5.7 and later you can use this.

mysqlpump -uroot -p${yourpasswd} --exclude-databases=% --users

This will generate a sql format output that you can redirect to mysql_users.sql.

Note that it is mysqlpump not mysqldump.

Answer 4

Yet another bash one-liner for linux that you can use instead of the Percona tool:

mysql -u<user> -p<password> -h<host> -N mysql -e "select concat(\"'\", user, \"'@'\", host, \"'\"), coalesce(password, authentication_string) from user where not user like 'mysql.%'" | while read usr pw ; do echo "GRANT USAGE ON *.* TO $usr IDENTIFIED BY PASSWORD '$pw';" ; mysql -u<user> -p<password> -h<host> -N -e "SHOW GRANTS FOR $usr" | grep -v 'GRANT USAGE' | sed 's/\(\S\)$/\1;/' ; done

Answer 5

In complement of @Sergey-Podushkin 's answer, this shell script code is workin for me:

mysql -u<user> -p<password> -N mysql -e "select concat(\"'\", user, \"'@'\", host, \"'\"), authentication_string from user where not user like 'root'" | while read usr pw ; do mysql -u<user> -p<password> -N -e "SHOW GRANTS FOR $usr" | sed 's/\(\S\)$/\1;/'; done 

Answer 6

PhpMyAdminYou can use phpMyAdmin.

Login and Go to your database or a table where the user has access.

Select privileges

All users with access are there.

Select Export. And a little window with all the GRANTS are there ready to copy and paste.

Answer 7

Here's what I'm using these days as part of my daily backup scripts (requires root shell and MySQL access, linux shell, and uses the mysql built-in schema:

First, I create a file /var/backup/mysqlroot.cnf containing the root password so I can automate my scripts and not hardcode any passwords in them:

[client]
password=(put your password here)

Then I create an export script which dumps create user commands and grants like this:

touch /var/backup/backup_sql.sh
chmod 700 /var/backup/backup_sql.sh
vi /var/backup/backup_sql.sh

And then write the following contents:

#!/bin/bash

mysql --defaults-extra-file=/var/backup/mysqlroot.cnf -sNe " \
  SELECT \
    CONCAT( 'CREATE USER \'', User, '\'@\'', Host, '\' IDENTIFIED BY \'', authentication_string, '\'\;' ) AS User \
  FROM mysql.user \
  WHERE \
    User NOT LIKE 'mysql.%' AND CONCAT( User, Host ) <> 'rootlocalhost' AND User <> 'debian-sys-maint' \
"

mysql --defaults-extra-file=/var/backup/mysqlroot.cnf -sNe " \
  SELECT \
    CONCAT( '\'', User, '\'@\'', Host, '\'' ) as User FROM mysql.user \
  WHERE \
    User NOT LIKE 'mysql.%' \
    AND CONCAT( User, Host ) <> 'rootlocalhost' \
    AND User <> 'debian-sys-maint' \
" | sort | while read u ; 
 do echo "-- $u"; mysql --defaults-extra-file=/var/backup/mysqlroot.cnf -sNe "show grants for $u" | sed 's/$/;/'
done

Then I just have to run it like this: /var/backup/backup_sql.sh > /tmp/exportusers.sql

Answer 8

I tackled this with a small C# program. There is code here to generate a script or apply the grants directly from source to destination. If porting from a Windows -> *nix environment you may have to consider case sensitivity issues.

using System;
using MySql.Data.MySqlClient;
using System.Configuration;
using System.IO;
using System.Collections.Generic;

namespace GenerateUsersScript
{
    class Program
    {
        static void Main(string[] args)
        {
            List<string> grantsQueries = new List<string>();

            // Get A Show Grants query for each user
            using (MySqlConnection sourceConn = OpenConnection("sourceDatabase"))
            {
                using (MySqlDataReader usersReader = GetUsersReader(sourceConn))
                {
                    while (usersReader.Read())
                    {
                        grantsQueries.Add(String.Format("SHOW GRANTS FOR '{0}'@'{1}'", usersReader[0], usersReader[1]));
                    }
                }

                Console.WriteLine("Exporting Grants For {0} Users", grantsQueries.Count);

                using (StreamWriter writer = File.CreateText(@".\UserPermissions.Sql"))
                {
                    // Then Execute each in turn 
                    foreach (string grantsSql in grantsQueries)
                    {
                        WritePermissionsScript(sourceConn, grantsSql, writer);
                    }

                    //using (MySqlConnection destConn = OpenConnection("targetDatabase"))
                    //{
                    //    MySqlCommand command = destConn.CreateCommand();

                    //    foreach (string grantsSql in grantsQueries)
                    //    {
                    //        WritePermissionsDirect(sourceConn, grantsSql, command);
                    //    }
                    //}
                }
            }

            Console.WriteLine("Done - Press A Key to Continue");

            Console.ReadKey();
        }

        private static void WritePermissionsDirect(MySqlConnection sourceConn, string grantsSql, MySqlCommand writeCommand)
        {
            MySqlCommand cmd = new MySqlCommand(grantsSql, sourceConn);

            using (MySqlDataReader grantsReader = cmd.ExecuteReader())
            {
                while (grantsReader.Read())
                {
                    try
                    {
                        writeCommand.CommandText = grantsReader[0].ToString(); 

                        writeCommand.ExecuteNonQuery();
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(grantsReader[0].ToString());

                        Console.WriteLine(ex.Message);
                    }
                }
            } 
        }

        private static void WritePermissionsScript(MySqlConnection conn, string grantsSql, StreamWriter writer)
        {
            MySqlCommand command = new MySqlCommand(grantsSql, conn);

            using (MySqlDataReader grantsReader = command.ExecuteReader())
            {
                while (grantsReader.Read())
                {
                    writer.WriteLine(grantsReader[0] + ";");
                }
            }

            writer.WriteLine();
        }

        private static MySqlDataReader GetUsersReader(MySqlConnection conn)
        {
            string queryString = String.Format("SELECT User, Host FROM USER");
            MySqlCommand command = new MySqlCommand(queryString, conn);
            MySqlDataReader reader = command.ExecuteReader();
            return reader;
        }

        private static MySqlConnection OpenConnection(string connName)
        {
            string connectionString = ConfigurationManager.ConnectionStrings[connName].ConnectionString;
            MySqlConnection connection = new MySqlConnection(connectionString);
            connection.Open();
            return connection; 

        }
    }
}

with an app.config containing ...

    <connectionStrings>
        <add name="sourceDatabase" connectionString="server=localhost;user id=hugh;password=xxxxxxxx;persistsecurityinfo=True;database=MySql" />
        <add name="targetDatabase" connectionString="server=queeg;user id=hugh;password=xxxxxxxx;persistsecurityinfo=True;database=MySql" />
    </connectionStrings> 

Answer 9

A PHP script to loop over your users to get the grant commands would be as such:

// Set up database root credentials
$host = 'localhost';
$user = 'root';
$pass = 'YOUR PASSWORD';
// ---- Do not edit below this ----
// Misc settings
header('Content-type: text/plain; Charset=UTF-8');
// Final import queries goes here
$export = array();
// Connect to database
try {
    $link = new PDO("mysql:host=$host;dbname=mysql", $user, $pass);
} catch (PDOException $e) {
    printf('Connect failed: %s', $e->getMessage());
    die();
}

// Get users from database
$statement = $link->prepare("select `user`, `host`, `password` FROM `user`");
$statement->execute();
while ($row = $statement->fetch())
{
    $user   = $row[0];
    $host   = $row[1];
    $pass   = $row[2];
    $export[] = "CREATE USER '{$user}'@'{$host}' IDENTIFIED BY '{$pass}'";
    // Fetch any permissions found in database
    $statement2 = $link->prepare("SHOW GRANTS FOR '{$user}'@'{$host}'");
    $statement2->execute();
    while ($row2 = $statement2->fetch())
    {
        $export[] = $row2[0];
    }
}

$link = null;
echo implode(";\n", $export);

Gist: https://gist.github.com/zaiddabaeen/e88a2d10528e31cd6692

Answer 10

    pass=your_password_here; \ 
    MYSQL_PWD=$pass mysql -B -N -uroot -e "SELECT CONCAT('\'', user,'\' ','\'', host,'\' ','\'', authentication_string,'\' ','\'', plugin,'\'') FROM mysql.user WHERE user != 'debian-sys-maint' AND user != 'root' AND user != 'mysql.sys' AND user != 'mysql.session' AND user != ''" > mysql_all_users.txt; \
    while read line; do linearray=(${line}); \
    MYSQL_PWD=$pass mysql -B -N -uroot -e "SELECT CONCAT('CREATE USER \'',${linearray[0]},'\'@\'',${linearray[1]},'\' IDENTIFIED WITH \'',${linearray[3]},'\' AS \'',${linearray[2]},'\'')"; \
        done < mysql_all_users.txt > mysql_all_users_sql.sql; \
    while read line; do linearray=(${line}); \
    MYSQL_PWD=$pass mysql -B -N -uroot -e "SHOW GRANTS FOR ${linearray[0]}@${linearray[1]}"; \
        done < mysql_all_users.txt >> mysql_all_users_sql.sql; \
    sed -e 's/$/;/' -i mysql_all_users_sql.sql; \
    echo 'FLUSH PRIVILEGES;' >> mysql_all_users_sql.sql; \
    unset pass

First mysql command : export all users to file and exclude some.
Second mysql command : loop users from file to write a sql command 'create user' to an exported file (with authentication credentials).
Third mysql command : loop users from file to append their privileges to the exported file.
sed command to append a ";" to end of lines and flush privileges to finish.
To import : MYSQL_PWD=$pass mysql -u root < mysql_all_users_sql.sql

Answer 11

SELECT CONCAT('\create user ', user,'\'@\'', host, '\' identified by ', "'", authentication_string, "'"'\;') FROM user WHERE user != 'mysql.session' AND user !='mysql.sys'  AND user != 'root' AND user != '';

Answer 12

I had the same problem. The solution is that after the import of the backup you need to do a "flush privileges;". Then the privileges of the users will be active as in the original database.

So execute:

mysql -u root -p -h localhost secondb < secondb_schema.sql

mysql -u root

then in mysql: flush privileges;