fix date format

apidata.py

@@ -72,7 +72,8 @@ def retrieveDataFromPostgres(query, cast_columns_to_types=None) :
     Internal method to select data using SQL query
     return a dataframe
     see read_sql_query() doc : https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.read_sql_query.html
-    columns can be type-casted using the cast_columns_to_types dictionary argument : { 'column_sql_name' : 'type'}. For 'type', see dtype String Aliases : https://pandas.pydata.org/docs/user_guide/basics.html#basics-dtypes
+    columns can be type-casted using the cast_columns_to_types dictionary argument : { 'column_sql_name' : 'type'}. 
+    For 'type', see dtype String Aliases : https://pandas.pydata.org/docs/user_guide/basics.html#basics-dtypes
     """
     #import pandas.io.sql as psql
     import pandas as pd
@@ -105,8 +106,10 @@ def formatCSV(mydataframe):
 def formatJSON(dataframe):
     """
     Internal method to output dataframe as JSON
+    https://pandas.pydata.org/pandas-docs/version/0.23/generated/pandas.DataFrame.to_json.html : says that date may be sent like epoch in ms
+    Added date_format='iso' to avoid this.
     """
-    json_str = json.dumps(dataframe.to_json(orient='records'))
+    json_str = json.dumps(dataframe.to_json(orient='records', date_format='iso'))
     return json.loads(json_str)
 
 def df_to_geojson(df, properties, id = 'ogc_fid', lat='y', lon='x'):
@@ -1149,8 +1152,20 @@ def getShipsDescription():
         occurences_class,  occurences_tonnageclass, captain_list, mindate, maxdate, nb_sourcedoc 
         from navigoviz.ship"""
 
-    
-    ## Warning, no comments have been set on ship table
+    #I've tried this, and it was working. Yet dates had dummy time zone inside (T00:00:00.000Z), e.g. 1787-01-02T00:00:00.000Z
+    #Thus, I've changed the type of mindate and maxdate to text fields in database (yyyy-mm-dd format)
+    cast_df_columns_to_types={
+        'ship_id' : 'string',
+        'occurences_names' : 'string',
+        'occurences_homeports' : 'string',
+        'occurences_flags' : 'string',
+        'occurences_class' : 'string',
+        'occurences_tonnageclass' :'string',
+        'captain_list':'string',
+        'mindate': 'datetime64[ns]', 
+        'maxdate' : 'datetime64[ns]',
+        'nb_sourcedoc': 'Int16'
+    }
     ## Si jamais on demande shortenFields= true, ca va planter.
     return retrieveDataAndFormatOutput(query, api='ships')
 
@@ -1178,9 +1193,7 @@ def getCaptainsDescription():
     query = f"""select captain_id, occurences_names, {localizedDatabaseFieldNames},
         ship_list, mindate, maxdate, nb_sourcedoc
         from navigoviz.captain"""
-
-    ##Warning, no comments have been set on captain table
-    ## Si jamais on demande shortenFields= true, ca va planter.
+    ## Si jamais on demande shortenFields= true, ca va planter.    
     return retrieveDataAndFormatOutput(query, api='captains')
 
 @app.route('/api/test/')

sql/portic_detailviz.sql

@@ -275,6 +275,7 @@ order by travel_rank;
 
 
 -- Renvoyer les variantes de noms de navires ou de capitaines
+-- role api_user / password portic
 GRANT USAGE ON SCHEMA navigoviz TO api_user;
 GRANT USAGE ON SCHEMA navigocheck to api_user;
 GRANT USAGE ON SCHEMA navigo to api_user;
@@ -331,6 +332,16 @@ alter table navigoviz.captain add column mindate date;
 alter table navigoviz.captain add column maxdate date;
 alter table navigoviz.captain add column nb_sourcedoc int;
 
+alter table navigoviz.ship alter column mindate type text;
+alter table navigoviz.ship alter column maxdate type text;
+-- alter table navigoviz.ship alter column mindate type date using mindate::date;
+-- alter table navigoviz.ship alter column maxdate type date using maxdate::date;
+-- alter table navigoviz.captain alter column mindate type date using mindate::date;
+-- alter table navigoviz.captain alter column maxdate type date using maxdate::date;
+alter table navigoviz.captain alter column mindate type text;
+alter table navigoviz.captain alter column maxdate type text;
+
+
 comment on column navigoviz.ship.captain_list is 'JSON array of various captains having sailed on the same ship through sources, with the frequecy of appearance in documents';
 comment on column navigoviz.ship.mindate is 'First date of appearance of this ship in the sources';
 comment on column navigoviz.ship.maxdate is 'Last date of appearance of this ship in the sources';
@@ -357,7 +368,7 @@ FROM
 WHERE s.ship_id = k.ship_id;	
 
 
-update navigoviz.ship s set mindate = k.mindate, maxdate=k.maxdate, nb_sourcedoc=k.nb
+update navigoviz.ship s set mindate = to_char(k.mindate, 'yyyy-mm-dd'), maxdate=to_char(k.maxdate, 'yyyy-mm-dd'), nb_sourcedoc=k.nb
 from (
 		Select ship_id, min(p.date_fixed) as mindate, max(p.date_fixed) as maxdate, count(distinct source_doc_id) as nb
 		FROM navigoviz.pointcall p
@@ -383,7 +394,7 @@ FROM
 WHERE s.captain_id = k.captain_id;
 
 
-update navigoviz.captain s set mindate = k.mindate, maxdate=k.maxdate, nb_sourcedoc=k.nb
+update navigoviz.captain s set mindate = to_char(k.mindate, 'yyyy-mm-dd'), maxdate=to_char(k.maxdate, 'yyyy-mm-dd'), nb_sourcedoc=k.nb
 from (
 		Select captain_id, min(p.date_fixed) as mindate, max(p.date_fixed) as maxdate, count(distinct source_doc_id) as nb
 		FROM navigoviz.pointcall p