![]() ![]() JOIN events_speakers es ON sp._id = es. Window Functions (windowfunctions.html) 2.1. If parameter Y is present then it is used as the separator A comma. JOIN events_terms et ON ts._id = et.term_id The groupconcat() function returns a string which is the concatenation of all non-NULL values of X. (group_concat(replace(distinct speakers.name),'',''), ' - ') AS term_names The CONCAT function returns a binary string if the arguments include any binary strings. The CONCAT function returns a nonbinary string if all arguments are nonbinary strings. ![]() It returns a single string as a result by concatenating all arguments. (group_concat(replace(distinct speakers.name),'',''), ' - ') AS speaker_names, CONCAT (string1, string2, string3, ) The CONCAT function may take one or more arguments. When you encapsulate the DISTINCT 'subquery' within a REPLACE method that actually does nothing you can have the relative simplicity of nawfal's suggestion without the drawback of only being able to concat comma-less strings properly. Since SQLite reports SQLite3::SQLException: DISTINCT aggregates must have exactly one argument, the problem seems not so much related to the GROUP_CONCAT method, but with using DISTINCT within GROUP_CONCAT. I ran accross this problem as well, but came up with a method that I found a bit easier to comprehend. ![]() I have created a gist which makes it easy for you to test a possible solution: Keep in mind this is a sqlite3 query I need, and I cannot add custom C aggregate functions, as this is for an Android deployment. It is a standard function of SQL that is a concat () function, it is used to concatenate the two different strings into a single string. My question is this: Is there a way I can form the query or change the data structures in order to get my desired results? I am left with these results: 1|Soccer|Bobby|Ball Problem: In MySQL lassen sich mit dem Befehl CONCAT die Inhalte aus mehreren Spalten miteinander kombinieren und sogar beliebige Strings hinzufügen. However, that doesn’t mean you can’t concatenate two strings in SQLite. The group_concat aggregate function has the ability to use 'distinct', which removes the duplication, though sadly it does not support that alongside the custom separator, which I really need. How to Concatenate Strings in SQLite Posted on by Ian SQLite doesn’t have a concat () function like many other database management systems, such as SQL Server’s concat () and MySQL’s concat (). However, when I run my query, I have duplication in the speaker_names and term_names values, since the join tables produce a row per association for each of the speakers and terms of the events: 1|Soccer|Bobby|BallĢ|Baseball|Bobby - Bobby - Bobby|Ball - Bat - Helmetsģ|Football|Bobby - Jane - Bobby - Jane|Ball - Ball - Helmets - Helmets sqlite >.open sakila. Given a table of "events" where each event may be associated with zero or more "speakers" and zero or more "terms", those records associated with the events through join tables, I need to produce a table of all events with a column in each row which represents the list of "speaker_names" and "term_names" associated with each event. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |