Create a dynamic SQL WHERE clause with optional date parameters

Data and Databases
1

Seeking an efficient method to build an SQL WHERE clause for optional start and end dates, avoiding cluttered nested conditions. Example:

def build_clause(start_date, end_date):
    if start_date and end_date:
        return f"date_column BETWEEN {start_date} AND {end_date}"
    elif start_date:
        return f"date_column >= {start_date}"
    elif end_date:
        return f"date_column <= {end_date}"
    return ""
2

Consider constructing the WHERE clause using a collection to append conditions. In my experience, using a list to gather segments and then combining them with a logical operator reduces redundant code. For example, if the start date exists, append the condition ‘date_column >= start_date’ to the list, and similarly for the end date. Once the list is populated, check if it contains any conditions and, if so, join them with ‘AND’. This approach enhances modularity and simplifies extending the logic in the future.