Migrations done in bash

migration.sh

#!/bin/bash

RUN_SQL?="$(which psql) i3"

function _info(){
    echo "At migration version: $(cat .migration-version)"
}

function _init() {
    echo 0 >  .migration-version
}

function _down(){
    MIGRATION=$1
    $RUN_SQL < $MIGRATION-down.sql
    echo $(($MIGRATION - 1)) > .migration-version
}

function _new() {
    VERSION=$(cat .migration-version)
    touch $((${VERSION} + 1))-up.sql
    touch $((${VERSION} + 1))-down.sql
    echo -n "edit up script? [y/n] "
    read ok
    if [ $ok = 'y' ] ; then
        exec $EDITOR $((${VERSION} + 1))-up.sql
    fi
}

function _up() {
    MIGRATION=$1
    $RUN_SQL < $MIGRATION-up.sql
    echo $MIGRATION > .migration-version
}


case $1 in
    info) _info ;;
    init) _init ;;
    down) _down $2 ;;
    new) _new $2 ;;
    up) _up $2 ;;
    *) echo "You need help, read ${0}" ;;
esac