Feature request: A way to inspect the query string run by asyncpg

[tommasosansone91]

I have hasked this before SO (https://stackoverflow.com/questions/69814471/is-there-a-way-to-inspect-the-query-string-run-by-asyncpg) but I am getting no answer, so this is a feature request.

---

When I use asyncpg to run a query on my database (and I have to run several queries),
I always split up things like this:

• the string of the query, with parameters placeholders:

  QUERY_1 = """
  UPDATE TABLE my_table 
  SET field_1 = $1
  WHERE field_id = $2;
  """
  

• a dictionary with the query parameters:

  query_params_dict = { 
      "field_1" : "value_1",
      "field_id" : "10"
  }
  

• and the function that will get the query string, replace the placeholders with the parameters values, run the query with connection.execute, and manage the errors:

  async def run_query_1(query_params_dict):
  	connection = await Utils.get_connection_to_db(**conf.asyncpg_db_conn) # custom function to open the connection to my db
  	query = QUERY_1
  	try:
  		await connection.execute(
  			query, query_params_dict["field_1"], int(query_params_dict["field_id"])
  		)
  		return None
  	except (Exception, asyncpg.UniqueViolationError) as integrError:
  		logger.error("Violated unique constraint: {}".format(integrError), exc_info=True)
  		return "{}".format(integrError)
  	except (Exception, asyncpg.ConnectionFailureError) as error:
  		logger.error("Failed connection: {}".format(error), exc_info=True)
  		return "{}".format(error)
  	finally:
  		if (connection):
  			await Utils.close_connection(connection)
  

But the queries I have to run often require many mores parameters, so that I always make some mistake in assigning values to the variables,
so that the query fails/returns unwanted results,
and the only way I know to determine what is wrong with it, is to check carefully the value assigned to every parameter of query_params_dict.

This takes a lot of time.
Instead, I could understand quickly what is wrong by checking the query run by asyncpg.

So, is there a way to inspect the query string run by asyncpg?

I would expect a command of asyncpg taking the same arguments of connection.execute as input, and returning as output the string of the query filled up with parameters, without running any query on the database.
Let's suppose this command exists and is connection.expected_query, in my case it would work like this:

connection.expected_query(
    			query, query_params_dict["field_1"], int(query_params_dict["field_id"])
>>>

"""
UPDATE TABLE my_table 
SET field_1 = 'value_1'
WHERE field_id = 10;
"""

Could you please implement a feature like this? Thanks in advance!

[forkexecve]

asyncpg does not perform argument interpolation. Instead the query text and the arguments are sent separately via PostgreSQL protocol. In other words, the interpolated query text you are looking for simply does not exist.