将日期列表传递给 SQL 查询

Question

I want to run a SQL query for pairs of dates from 2020 to now. I can make the list in this loop:

rep_dates = list(pd.date_range(start='2020-07-31',
              end='2022-09-30',
              freq='1M').strftime('%Y-%m-%d'))

df_list = [0 for i in range(len(rep_dates))]
for i in range(len(rep_dates)):#, obs_date in enumerate(rep_dates):
    df_list[i]=[rep_dates[i-1],rep_dates[i]]
    
df_list.pop(0)

Now I want to run this SQL query:

staging=run_sql('''select
cast('{prev_rep_date}' as date) as reporting_date
from (select * from database where l_reportdate = '{prev_rep_date}') as m_1
join (select * from database where l_reportdate = '{rep_date}') as m on m.brw_pk = m_1.brw_pk
''')

With my pairs labelled as prev_rep_date and rep_date - how can I pass them to the query?

Thanks for any suggestions: :)

Answer 1

If I understand correcty, f-strings should solve your problem. This will run your query for all the pairs, probably you should store the results from the loop in a dataframes or lists, thats up to you.

for x in df_list:
    prev_rep_date = x[0]
    rep_date = x[1]
    sql_stmt = f'''
                select
                cast('{prev_rep_date}' as date) as reporting_date
                from (select * from database where l_reportdate = '{prev_rep_date}') as m_1
                join (select * from database where l_reportdate = '{rep_date}') as m on m.brw_pk = m_1.brw_pk
                '''
    staging = run_sql(sql_stmt)