How to Pass Dictionary Parameters to Pandas `read_sql` for SQL Queries?

Use Pandas read_sql to pass parameters for SQL query

When querying a database from Pandas using SQLAlchemy, you often need to pass parameters to the SQL query. While the documentation recommends using parameter lists or tuples, this post explores the feasibility of using a dictionary.

Specifically, the question is what is the recommended syntax for passing SQL query parameters from Pandas using a dictionary.

Use named parameters

According to the read_sql documentation, parameters can be passed as a list, tuple, or dictionary. However, the syntax for passing values ​​in SQL queries depends on the database driver used.

For PostgreSQL using the psycopg2 driver, named parameters are supported using the %(name)s style. Here's an example:

<code class="language-python">df = psql.read_sql(('select "Timestamp", "Value" from "MyTable" '
                     'where "Timestamp" BETWEEN %(dstart)s AND %(dfinish)s'),
                   db,
                   params={"dstart": datetime(2014, 6, 24, 16, 0), "dfinish": datetime(2014, 6, 24, 17, 0)},
                   index_col=["Timestamp"])</code>

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