# How to Create Prepared Statements with the Airflow PostgresOperator

Airflow's [PostgresOperator](https://airflow.apache.org/docs/apache-airflow-providers-postgres/stable/_api/airflow/providers/postgres/operators/postgres/index.html) includes a field called `parameters` for providing SQL parameters for [prepared statements](https://en.wikipedia.org/wiki/Prepared_statement).

We wanted to use named parameters since our parameter order would vary, which meant [understanding the syntax](https://airflow.apache.org/docs/apache-airflow-providers-postgres/stable/operators/postgres_operator_howto_guide.html#passing-parameters-into-postgresoperator). In their provided example: `SELECT * FROM pet WHERE birth_date BETWEEN SYMMETRIC %(begin_date)s AND %(end_date)s`, the format here was unclear - for example the trailing `s` (we guessed this meant `string`, but queries with numerical inputs were failing without the s.

After some research we realized that the underlying dependency here was [Psycopg](https://www.psycopg.org/psycopg3/docs/basic/params.html). From this page:

```
Named arguments are supported too using %(name)s placeholders in the query and specifying the values into a mapping. Using named arguments allows to specify the values in any order and to repeat the same value in several places in the query:
```

and:

```
The variables placeholder must always be a %s, even if a different placeholder (such as a %d for integers or %f for floats) may look more appropriate for the type.
```

So, follow the above format for your variable placeholders, and ensure that the variable passed in is cast to the correct format (i.e. don't quote numbers).