query = ('SELECT ? from table', fields)
Example of ‘fields’ value = name, surname, date
I can put ‘fields’ in a list but I do not know how many (?) to put inside the query. Because, fields variable will include sometimes 5, sometimes 10 column names. I am trying to pass column names dynamically to the query.
How can I solve this problem?
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Answer
A statement could be formed like so. Values will be like “(?, ?, ?, ?)” depending on the length of fields.
# create a comma separated list of question marks
# then surround with parenthesis
values = '('+', '.join(['?']*len(fields))+')'
query=('SELECT '+values+' from table',fields)
Not saying that this will work since you didn’t share specifics of how you are connecting to or querying SQL Server.
Instead you could use the join str method:
table_name = 'MyTable'
fields = ['col1','col2','col3']
values = ', '.join(fields)
statement = 'SELECT '+values+' from '+table_name
query
'SELECT col1, col2, col3 from MyTable'
query=(statement)