How to use variables in SQL query when using Python and pyodbc - sql

Question

I am using Python to extract data from SQL by using ODBC to linking Python to SQL database. when I do the query, I need to use variables in the query to make my query result changeable. For example, my code is:
import pyodbc
myConnect = pyodbc.connect('DSN=B1P HANA;UID=***;PWD=***')
myCursor = myConnect.cursor()
Start = 20180501
End = 20180501
myOffice = pd.Series([1,2,3])
myRow = myCursor.execute("""
SELECT "CALDAY" AS "Date",
"/BIC/ZSALE_OFF" AS "Office"
FROM "SAPB1P"."/BIC/AZ_RT_A212"
WHERE "CALDAY" BETWEEN 20180501 AND 20180501
GROUP BY "CALDAY","/BIC/ZSALE_OFF"
""")
Result = myRow.fetchall()
d = pd.DataFrame(columns=['Date','Office'])
for i in Result:
d= d.append({'Date': i.Date,
'Office': i.Office},
ignore_index=True)
You can see that I retrieve data from SQL database and save it into a list (Result), then I convert this list to a data frame (d).
But, my problems are:
I need to specify a start date and an end data in myCursor.execute part, something like "CALDAY" BETWEEN Start AND End
Let's say I have 100 offices in my data. Now I just need 3 of them (myOffice). So, I need to put a condition in myCursor.execute part, like myOffice in (1,2,3)
In R, I know how to deal with these two problems. the code is like:
office_clause = ""
if (myOffice != 0) {
office_clause = paste(
'AND "/BIC/ZSALE_OFF" IN (',paste(myOffice, collapse=", "),')'
)
}
a <- sqlQuery(ch,paste(' SELECT ***
FROM ***
WHERE "CALDAY" BETWEEN',Start,'AND',End,'
',office_clause1,'
GROUP BY ***
'))
But I do not know how to do this in Python. How can I do this?

Answer 1

You can use string formatting operations for this.
First define
query = """
SELECT
"CALDAY" AS "Date",
"/BIC/ZSALE_OFF" AS "Office"
FROM
"SAPB1P"."/BIC/AZ_RT_A212"
WHERE
"CALDAY" BETWEEN {start} AND {end}
{other_conds}
GROUP BY
"CALDAY","/BIC/ZSALE_OFF"
"""
Now you can use
myRow = myCursor.execute(query.format(
start='20180501'
end='20180501',
other_conds=''))
and
myRow = myCursor.execute(query.format(
start='20180501'
end='20180501',
other_conds='AND myOffice IN (1,2,3)'))