TGIS DB v3 backward compatible with v2 (#1454)

Co-authored-by: Markus Neteler <neteler@gmail.com>

lib/temporal/SQL/update_strds_metadata_template.sql

@@ -41,9 +41,3 @@ UPDATE strds_metadata SET ewres_max =
        (SELECT max(ewres) FROM raster_metadata WHERE raster_metadata.id IN 
     		(SELECT id FROM SPACETIME_REGISTER_TABLE)
        ) WHERE id = 'SPACETIME_ID';
--- Update the number of registered bands
-UPDATE strds_metadata SET number_of_bands =
-       (SELECT count(distinct semantic_label) FROM raster_metadata WHERE
-       raster_metadata.id IN
-    		(SELECT id FROM SPACETIME_REGISTER_TABLE)
-       ) WHERE id = 'SPACETIME_ID';

lib/temporal/SQL/update_strds_metadata_template_v3.sql

@@ -0,0 +1,15 @@
+--#############################################################################
+-- This SQL is to update a space-time raster dataset metadata (version 3+)
+--
+-- Author: Soeren Gebbert soerengebbert <at> googlemail <dot> com
+--#############################################################################
+
+-- SPACETIME_REGISTER_TABLE is a placeholder for specific stds map register table name (SQL compliant)
+-- SPACETIME_ID is a placeholder for specific stds id: name@mapset
+
+-- Update the number of registered bands
+UPDATE strds_metadata SET number_of_bands =
+       (SELECT count(distinct semantic_label) FROM raster_metadata WHERE
+       raster_metadata.id IN
+               (SELECT id FROM SPACETIME_REGISTER_TABLE)
+       ) WHERE id = 'SPACETIME_ID';

python/grass/temporal/abstract_space_time_dataset.py

@@ -22,6 +22,7 @@ class that is the base class for all space time datasets.
     get_tgis_metadata,
     get_current_mapset,
     get_enable_mapset_check,
+    get_tgis_db_version_from_metadata,
 )
 from .abstract_dataset import AbstractDataset, AbstractDatasetComparisonKeyStartTime
 from .temporal_granularity import (
@@ -2513,7 +2514,6 @@ def update_from_registered_maps(self, dbif=None):
 
         :param dbif: The database interface to be used
         """
-
         if (
             get_enable_mapset_check() is True
             and self.get_mapset() != get_current_mapset()
@@ -2576,6 +2576,17 @@ def update_from_registered_maps(self, dbif=None):
             ),
             "r",
         ).read()
+
+        for version in range(3, get_tgis_db_version_from_metadata() + 1):
+            sqlfile = os.path.join(
+                sql_path,
+                "update_"
+                + self.get_type()
+                + "_metadata_template_v{}.sql".format(version),
+            )
+            if os.path.exists(sqlfile):
+                sql += open(sqlfile).read()
+
         sql = sql.replace("SPACETIME_REGISTER_TABLE", stds_register_table)
         sql = sql.replace("SPACETIME_ID", self.base.get_id())
 

python/grass/temporal/core.py

@@ -363,8 +363,8 @@ def get_raise_on_error():
 
 
 def get_tgis_version():
-    """Get the version number of the temporal framework
-    :returns: The version number of the temporal framework as string
+    """Get the supported version of the temporal framework
+    :returns: The version number of the temporal framework as integer
     """
     global tgis_version
     return tgis_version
@@ -374,13 +374,29 @@ def get_tgis_version():
 
 
 def get_tgis_db_version():
-    """Get the version number of the temporal framework
-    :returns: The version number of the temporal framework as string
+    """Get the supported version of the temporal database
+    :returns: The version number of the temporal database as integer
     """
     global tgis_db_version
     return tgis_db_version
 
 
+def get_tgis_db_version_from_metadata(metadata=None):
+    """Get the version number of the temporal database from metadata
+
+    :param list metadata: list of metadata items or None
+    :returns: The version number of the temporal database as integer
+    """
+    if metadata is None:
+        metadata = get_tgis_metadata()
+    for entry in metadata:
+        if "tgis_db_version" in entry:
+            return int(entry[1])
+
+    # return supported version if not possible to get from metadata
+    return get_tgis_db_version()
+
+
 ###############################################################################
 
 
@@ -697,10 +713,7 @@ def init(raise_fatal_error=False, skip_db_version_check=False):
             db_exists = True
 
     backup_howto = _(
-        "The format of your actual temporal database is not "
-        "supported any more.\n"
-        "Please create a backup of your temporal database "
-        "to avoid lossing data.\nSOLUTION: "
+        "Please create a backup of your temporal database to avoid losing data.\n"
     )
     if tgis_db_version > 2:
         backup_howto += _("Run t.upgrade command to upgrade your temporal database.\n")
@@ -738,6 +751,8 @@ def init(raise_fatal_error=False, skip_db_version_check=False):
                 )
                 % ({"info": get_database_info_string()})
             )
+
+        # temporal framework version check
         for entry in metadata:
             if "tgis_version" in entry and entry[1] != str(get_tgis_version()):
                 msgr.fatal(
@@ -756,22 +771,33 @@ def init(raise_fatal_error=False, skip_db_version_check=False):
                         }
                     )
                 )
-            if "tgis_db_version" in entry and entry[1] != str(get_tgis_db_version()):
+
+        # temporal database version check
+        tgis_db_version_meta = get_tgis_db_version_from_metadata(metadata)
+        if tgis_db_version_meta != tgis_db_version:
+            message = _(
+                "Temporal database version mismatch detected.\n{backup}"
+                "Supported temporal database version is: {tdb}\n"
+                "Your existing temporal database version: {ctdb}\n"
+                "Current temporal database info: {info}".format(
+                    backup=backup_howto,
+                    tdb=tgis_db_version,
+                    ctdb=tgis_db_version_meta,
+                    info=get_database_info_string(),
+                )
+            )
+
+            if tgis_db_version_meta == 2 and tgis_db_version == 3:
+                # version 3 is backward compatible with version 2
+                msgr.warning(message)
+            else:
                 msgr.fatal(
                     _(
-                        "Unsupported temporal database: version mismatch."
-                        "\n %(backup)sSupported temporal database version"
-                        " is: %(tdb)i\nCurrent temporal database info:"
-                        "%(info)s"
-                    )
-                    % (
-                        {
-                            "backup": backup_howto,
-                            "tdb": get_tgis_version(),
-                            "info": get_database_info_string(),
-                        }
+                        "The format of your actual temporal database is "
+                        "not supported any more. {m}".format(m=message)
                     )
                 )
+
         return
 
     create_temporal_database(dbif)

python/grass/temporal/metadata.py

@@ -23,7 +23,7 @@
 """
 from __future__ import print_function
 from .base import SQLDatabaseInterface
-from .core import SQLDatabaseInterfaceConnection
+from .core import SQLDatabaseInterfaceConnection, get_tgis_db_version_from_metadata
 
 ###############################################################################
 
@@ -355,7 +355,8 @@ def __init__(
             max,
         )
 
-        self.set_semantic_label(semantic_label)
+        if get_tgis_db_version_from_metadata() > 2:
+            self.set_semantic_label(semantic_label)
 
     def set_semantic_label(self, semantic_label):
         """Set the semantic label identifier"""
@@ -1372,7 +1373,8 @@ def __init__(self, ident=None, raster_register=None, title=None, description=Non
             self, "strds_metadata", ident, title, description
         )
 
-        self.D["number_of_bands"] = None
+        if get_tgis_db_version_from_metadata() > 2:
+            self.D["number_of_bands"] = None
 
         self.set_raster_register(raster_register)
 
@@ -1403,6 +1405,9 @@ def get_band_names(self):
            and fetched on-the-fly
         :return: None if not found
         """
+        if get_tgis_db_version_from_metadata() <= 2:
+            # band names supported from TGIS DB version 3
+            return None
 
         sql = "SELECT distinct semantic_label FROM %s WHERE %s.id " % (
             "raster_metadata",