The following python code is initially created to practice SQL queries on four
tables:

beers(name, manf) -- beer name and beer manufacturer
sells(bar, beer, price) - bar sell beer at price
frequents(drinker, bar) - drinker frequently goes to bar
likes(drinker, beer) - drinker like beer

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Files:

sql_README.txt: this file
sql_init_tables.py: create initial tables and their conent
sql_display_table.py: show the content of a table
sql_list_tables.py: list all tables in the database
sql_run_query.py: run an SQL query statement
sql_run_modification.py: run an SQL database modification statement (
create table, insert, delete, update an item, etc)
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To run the system, first run sql_init_tables.py ('python3 sql_init_tables.py')

After that you can see the content of tables using sql_display_table.py

python3 sql_display_table.py beer
python3 sql_display_table.py sells
python3 sql_display_table.py frequents
python3 sql_display_table.py likes

List all tables in the database with 'python3 sql_list_tables.py'.

You can then put your SQL query on the four tables in a file
(e.g. myquery.txt), run the query and see the output with the following
command:

python3 sql_run_query.py myquery.txt

You can put SQL database modification statement in a file (e.g. a.txt),
and run the statement with

python3 sql_run_modification a.txt