SQLAlchemy Postgresql database django

I am new to Django and have a question in regards to whether or not I have to re-enter data or can use existing data from a postgres database and apologize if this has been asked before. I have a Postgres database in which I created with SQLAlchemy ORM. I use this database for data… Read More SQLAlchemy Postgresql database django

getting elements with a queryset based on a left join in django

I have two models: class A(models.Model): field1 = models.CharField(max_length=100) field2 = models.CharField(max_length=100) class B(models.Model): a_field = models.ForeignKey(null=True,blank=True,related_name=’a’,on_delete=models.SET_NULL) field2 = models.CharField(max_length=100) I want to get all of elements of model A which are not related to B. Here is the query I wrote but it doesn’t work: B.objects.select_related("a_field").filter(a_field__isnull=True) How can I solve this problem? >Solution :… Read More getting elements with a queryset based on a left join in django

How to change selected value text color in DropdownButtonFormField?

I am using dropdownbuttonformfield for creating dropdown. I need to change selected value text color white and dropdown items text color should be black as shown in image. I need to change color for image 1. image 1 image 2 >Solution : selectedItemBuilder: (context) { final List<DropdownMenuItem<String>> list = []; for (int i = 0;… Read More How to change selected value text color in DropdownButtonFormField?

solving nested renamer is not supported with dynamic arguments

if cat_vars: df["static_cat"] = ( df.groupby("group_col") .agg({i: "first" for i in cat_vars}) .values.tolist() ) Error: packages\pandas\core\groupby\generic.py in aggregate(self, func, *args, **kwargs) 926 func = _maybe_mangle_lambdas(func) 927 –> 928 result, how = self._aggregate(func, *args, **kwargs) 929 if how is None: 930 return result packages\pandas\core\base.py in _aggregate(self, arg, *args, **kwargs) 355 obj.columns.intersection(keys) 356 ) != len(keys): –>… Read More solving nested renamer is not supported with dynamic arguments

SQL Join Using REGEXP_SUBSTR and Wildcard

I’m trying to join two tables in Snowflake using REGEX_SUBSTR and a wildcard but having no luck. Here is what I have: SELECT P.NAME, ACL.CONTENT_NAME, REGEXP_SUBSTR(CONTENT_NAME, ‘/([^/]+(\\.pdf))$’, 1, 1, ‘e’, 1) AS PDFS FROM ACTIVITY_DOWNLOAD AD JOIN PROGRAM P ON P.NAME LIKE ‘%’ || REGEXP_SUBSTR(CONTENT_NAME, ‘/([^/]+(\\.pdf))$’, 1, 1, ‘e’, 1) || ‘%’ Running the query… Read More SQL Join Using REGEXP_SUBSTR and Wildcard