Finally got answer from Flask documentation, we can get cursor from db object using, from sqlalchemy import create_engine engine = create_engine(‘your_connection_string’) connection = engine.raw_connection() cursor = connection.cursor()
Just a hunch, but normally a TOP-ORDER BY requires SQL Server to buffer the result in some way (either the index scan’s result or indeed the entire result in a temp structure, or anything in between). One could argue that for cursors this is also necessary even when ordering by the primary key (as in … Read more
you need to declare your cursor as scroll, like this declare c scroll cursor for (select statement); then at any time for locating to the first just use the following fetch first from c;
It depends on whether you declared the cursor locally or globally (and what the default is in your environment – default is global but you can change it). If the cursor is global, then it can stay “alive” in SQL Server until the last piece of code is touched in the scope in which it … Read more
Total cursors open, by session: select a.value, s.username, s.sid, s.serial# from v$sesstat a, v$statname b, v$session s where a.statistic# = b.statistic# and s.sid=a.sid and b.name=”opened cursors current”; Source: http://www.orafaq.com/node/758 As far as I know queries on v$ views are based on pseudo-tables (“x$” tables) that point directly to the relevant portions of the SGA, so … Read more
I am in agreement with Otto Allmendinger’s answer, but to make explicit Denis Otkidach’s comment, here is how you can iterate over the results without using Otto’s fetch() function: import MySQLdb.cursors connection=MySQLdb.connect( host=”thehost”,user=”theuser”, passwd=”thepassword”,db=”thedb”, cursorclass = MySQLdb.cursors.SSCursor) cursor=connection.cursor() cursor.execute(query) for row in cursor: print(row)
Cursors are a mechanism to explicitly enumerate through the rows of a result set, rather than retrieving it as such. However, while they may be more comfortable to use for programmers accustomed to writing While Not RS.EOF Do …, they are typically a thing to be avoided within SQL Server stored procedures if at all … Read more
The main reason that I’m aware of is that set-based operations can be optimised by the engine by running them across multiple threads. For example, think of a quicksort – you can separate the list you’re sorting into multiple “chunks” and sort each separately in their own thread. SQL engines can do similar things with … Read more