use nulltype condition in nulltype check when inserting #284

	name: Valve Tests

	on:
	pull_request:
	types:
	- ready_for_review
	push:
	branches:
	- '*'
	env:
	CARGO_TERM_COLOR: always
	jobs:
	run-tests:
	runs-on: ubuntu-20.04
	steps:
	- name: Install postgresql server and client
	run: \|
	sudo apt-get update
	sudo apt-get install postgresql postgresql-contrib postgresql-client build-essential
	sudo mkdir /opt/sqlite3
	wget https://www.sqlite.org/2023/sqlite-autoconf-3430000.tar.gz
	tar xvfz sqlite-autoconf-3430000.tar.gz
	sudo mv sqlite-autoconf-3430000 /opt/sqlite3
	cd /opt/sqlite3/sqlite-autoconf-3430000
	./configure
	make -j 2
	sudo make install
	- name: Start the database server
	run: \|
	sudo systemctl start postgresql.service
	- name: Create the valve_postgres database
	run: \|
	sudo su - postgres -c "createuser runner"
	sudo su - postgres -c "createdb -O runner valve_postgres"
	- name: Setup python
	uses: actions/setup-python@v4
	with:
	python-version: '3.8'
	- name: Check out repository code
	uses: actions/checkout@v3
	- name: Install psycopg2
	run: \|
	pip3 install -r requirements.txt
	- name: Run tests on both sqlite and on postgresql
	run: \|
	make test

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