sqlalchemy IS NOT NULL select
python, sqlalchemy
Solution
`column_obj != None` will produce a `IS NOT NULL` constraint:
In a column context, produces the clause `a != b`. If the target is `None`, produces a `IS NOT NULL`.
or use `is_not()`*:
Implement the `IS NOT` operator.
Normally, `IS NOT` is generated automatically when comparing to a value of `None`, which resolves to `NULL`. However, explicit usage of `IS NOT` may be desirable if comparing to boolean values on certain platforms.
Demo:
>>> from sqlalchemy.sql import column
>>> column('YourColumn') != None
<sqlalchemy.sql.elements.BinaryExpression object at 0x10f81aa90>
>>> print(column('YourColumn') != None)
"YourColumn" IS NOT NULL
>>> column('YourColumn').is_not(None)
<sqlalchemy.sql.elements.BinaryExpression object at 0x11081edf0>
>>> print(column('YourColumn').is_not(None))
"YourColumn" IS NOT NULL
You can't use `is not None` here, because the `is not` object identity inequality test can't be overloaded the way `!=` can; you'll just get `True` instead as a `ColumnClause` instance is not the same object as the `None` singleton:
>>> column('YourColumn') is not None
True
*) The method was formerly named `isnot()` and was renamed in SQLAlchemy 1.4. The old name is still available for backwards compatibility.
Problem
How can I add the filter as in SQL to select values that are NOT NULL from a certain column ? ``` SELECT * FROM table WHERE YourColumn IS NOT NULL; ``` How can I do the same with SQLAlchemy filters? ``` select = select(table).select_from(table).where(all_filters) ```