retain the data inside database using docker

I have created database.sql file and added to a folder inside the container so that it can be used by the application.I want that my data should remain persistent even when my container is removed.I tried using volume.But how to add .sql file and make that file consistent.

sudo docker -v /datadir sqldb 

here, sqldb is database image name and datadir is mount folder.

Dockerfile of sqldb:

FROM ubuntu:latest

RUN apt-get update
RUN apt-get upgrade -y

RUN apt-get -y install mysql-client mysql-server curl
ADD ./my.cnf /etc/mysql/my.cnf

RUN sed -i -e"s/^bind-address\s*=\s*127.0.0.1/bind-address = 0.0.0.0/" /etc/mysql/my.cnf

ADD database.sql /var/db/database.sql

ENV user root
ENV password password
ENV url file:/var/db/database.sql
ENV right WRITE

ADD ./start-database.sh /usr/local/bin/start-database.sh
RUN chmod +x /usr/local/bin/start-database.sh
EXPOSE 3306

CMD ["/usr/local/bin/start-database.sh"]

start-database.sh file

#!/bin/bash

# This script starts the database server.
echo "Creating user $user for databases loaded from $url"
a
# Import database if provided via 'docker run --env url="http:/ex.org/db.sql"'
echo "Adding data into MySQL"
/usr/sbin/mysqld &
sleep 5
curl $url -o import.sql

# Fixing some phpmysqladmin export problems
sed -ri.bak 's/-- Database: (.*?)/CREATE DATABASE \1;\nUSE \1;/g' import.sql

# Fixing some mysqldump export problems (when run without --databases switch)
# This is not tested so far
# if grep -q "CREATE DATABASE" import.sql; then :; else sed -ri.bak 's/-- MySQL dump/CREATE DATABASE `database_1`;\nUSE `database_1`;\n-- MySQL dump/g' import.sql; fi

mysql --default-character-set=utf8 < import.sql
rm import.sql
mysqladmin shutdown
echo "finished"

# Now the provided user credentials are added
/usr/sbin/mysqld &
sleep 5
echo "Creating user"
echo "CREATE USER '$user' IDENTIFIED BY '$password'" | mysql --default-character-set=utf8
echo "REVOKE ALL PRIVILEGES ON *.* FROM '$user'@'%'; FLUSH PRIVILEGES" | mysql --default-character-set=utf8
echo "GRANT SELECT ON *.* TO '$user'@'%'; FLUSH PRIVILEGES" | mysql --default-character-set=utf8
echo "finished"

if [ "$right" = "WRITE" ]; then 
echo "adding write access"
echo "GRANT ALL PRIVILEGES ON *.* TO '$user'@'%' WITH GRANT OPTION; FLUSH PRIVILEGES" | mysql --default-character-set=utf8
fi

# And we restart the server to go operational
mysqladmin shutdown
cp /var/db/database.sql /var/lib/docker/volumes/mysqlvol/database.sql
echo "Starting MySQL Server"
/usr/sbin/mysqld