-#DOWNGRADE DATABASE step by step
-while [ $DB_VERSION -lt $DATABASE_VER_NUM ]
-do
- echo " downgrade database from version '$DATABASE_VER_NUM' to '$((DATABASE_VER_NUM-1))'"
- #FILE_="${DIRNAME}/downgrade_from_${DATABASE_VER_NUM}.sh"
- #[ ! -x "$FILE_" ] && echo "Error, can not find script '$FILE_' to downgrade" >&2 && exit -1
- #$FILE_ || exit -1 # if fail return
- downgrade_from_${DATABASE_VER_NUM}
- DATABASE_VER_NUM=$((DATABASE_VER_NUM-1))
-done
+ #DOWNGRADE DATABASE step by step
+ while [ $DB_VERSION -lt $DATABASE_VER_NUM ]
+ do
+ echo " downgrade database from version '$DATABASE_VER_NUM' to '$((DATABASE_VER_NUM-1))'"
+ #FILE_="${DIRNAME}/downgrade_from_${DATABASE_VER_NUM}.sh"
+ #[ ! -x "$FILE_" ] && echo "Error, can not find script '$FILE_' to downgrade" >&2 && exit -1
+ #$FILE_ || exit -1 # if fail return
+ downgrade_from_${DATABASE_VER_NUM}
+ DATABASE_VER_NUM=$((DATABASE_VER_NUM-1))
+ done
+}
+
+
+# check if current database is ok
+function check_migration_needed()
+{
+ DATABASE_VER_NUM=`echo "select max(version_int) from schema_version;" | $DBCMD | tail -n+2` ||
+ ! echo " ERROR cannot read from schema_version" || exit 1
+
+ if [[ -z "$DATABASE_VER_NUM" ]] || [[ "$DATABASE_VER_NUM" -lt 0 ]] || [[ "$DATABASE_VER_NUM" -gt 100 ]] ; then
+ echo " Error can not get database version ($DATABASE_VER_NUM?)" >&2
+ exit 1
+ fi
+
+ [[ $DB_VERSION -eq $DATABASE_VER_NUM ]] && echo " current database version '$DATABASE_VER_NUM' is ok" && return 1
+ [[ "$DATABASE_VER_NUM" -gt "$LAST_DB_VERSION" ]] &&
+ echo "Database has been upgraded with a newer version of this script. Use this version to downgrade" >&2 &&
+ exit 1
+ return 0
+}
+
+DATABASE_PROCESS=`echo "select comments from schema_version where version_int=0;" | $DBCMD | tail -n+2` ||
+ ! echo " ERROR cannot read from schema_version" || exit 1
+if [[ -z "$DATABASE_PROCESS" ]] ; then # migration a non empty database
+ check_migration_needed || exit 0
+ # Create a backup database content
+ [[ -n "$BACKUP_DIR" ]] && BACKUP_FILE="$(mktemp -q "${BACKUP_DIR}/backupdb.XXXXXX.sql")"
+ [[ -z "$BACKUP_DIR" ]] && BACKUP_FILE="$(mktemp -q --tmpdir "backupdb.XXXXXX.sql")"
+ mysqldump $DEF_EXTRA_FILE_PARAM --add-drop-table --add-drop-database --routines --databases $DBNAME > $BACKUP_FILE ||
+ ! echo "Cannot create Backup file '$BACKUP_FILE'" >&2 || exit 1
+ echo " Backup file '$BACKUP_FILE' created"
+ # Set schema version
+ set_schema_version_process
+ migrate
+ del_schema_version_process
+ rm -f "$BACKUP_FILE"
+elif echo $DATABASE_PROCESS | grep -q init ; then # Empty database. No backup needed
+ echo " Migrating an empty database"
+ if check_migration_needed ; then
+ migrate
+ fi
+ del_schema_version_process
+
+else # Recover Migration process
+ BACKUP_FILE=${DATABASE_PROCESS##*backup: }
+ [[ -f "$BACKUP_FILE" ]] || ! echo "Previous migration process fail and cannot recover backup file '$BACKUP_FILE'" >&2 ||
+ exit 1
+ echo " Previous migration was killed. Restoring database from rollback file'$BACKUP_FILE'"
+ cat $BACKUP_FILE | mysql $DEF_EXTRA_FILE_PARAM || ! echo " Cannot load backup file '$BACKUP_FILE'" >&2 || exit 1
+ if check_migration_needed ; then
+ set_schema_version_process
+ migrate
+ fi
+ del_schema_version_process
+ rm -f "$BACKUP_FILE"
+fi
+exit 0