On Sun, Feb 21, 2016 at 6:09 PM, Olivier Mascia <om at integral.be> wrote:
> Dear all, > > Is it possible to implement a SQL function ( > https://www.sqlite.org/c3ref/create_function.html), which implementation > would be able to return the same value for the duration of the current > transaction? > This _might_ suffice for you, but maybe not: the SQLITE_DETERMINISTIC flag for sqlite3_create_function(). Copied from the header file: ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] ** to signal that the function will always return the same result given ** the same inputs within a single SQL statement. Most SQL functions are ** deterministic. The built-in [random()] SQL function is an example of a ** function that is not deterministic. The SQLite query planner is able to ** perform additional optimizations on deterministic functions, so use ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. Note that it says within a single statement, not a transaction. -- ----- stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal "Freedom is sloppy. But since tyranny's the only guaranteed byproduct of those who insist on a perfect world, freedom will have to do." -- Bigby Wolf
