I have a database of restaurants which I do a full-text search on. The code looks something like this:
SELECT * FROM restaurant WHERE restaurant.search_vector ## plainto_tsquery(:terms);
And search_vector is defined like this:
alter table restaurant add column search_vector tsvector;
create index restaurant_search_index on restaurant using gin(search_vector);
create trigger restaurant_search_update before update or insert on restaurant
for each row execute procedure
tsvector_update_trigger('search_vector',
'pg_catalog.english','title');
Now, a notable problem with this search is the word barbecue. It can be spelled many different ways: barbecue, barbeque, BBQ, B.B.Q., B-B-Q, etc. When somebody searches any of these, I need to search restaurants for all of these terms.
From what I've read online, it seems I need to modify the dictionary (That would be pg_catalog.english, right?), but I'm not sure how to go about this.
Sounds like what you want to do is add a synonym dictionary in front of your english one. This will only work on single words though, so you might have problems with B.B.Q. if it gets parsed as three separate tokens.
Synonym dictionaries in postgresql.org docs
When I drumbled over a similiar problem I came across the option for Query Rewrites, see http://www.postgresql.org/docs/8.3/static/textsearch-features.html forexample, section 12.4.2.1
This is an easier approach then tackling the dictionary as it allows instantly extending your rewrite rules by just inserting new rules in your rewrite table.
Related
What's the optimal way to store values for a select list in a web-app with Postgres?
If I use an enum, this has the benefit of acting as a constraint for whatever column is set to that type (only allowing possible values). I can also write rather normal queries to pull those values to populate the select... but this has the drawback of requiring the option text and value to be identical.
If I create a table to store these, I can have columns for both value and text, and perhaps even a third (comment/description, whatever). However, it means a full table for every set of values, of which I expect several dozen throughout the webapp. Not sure why this feels like a "heavier" solution than enums, but it does. (A "create enum" statement plus possible "alter enum" in the future vs. a "create table" plus many initial insert statements and maybe more in the future.)
Nor can I create a single table for all dropdown lists, because then I would need to do convoluted constraint logic in the various tables that related to that.
Is there a code pattern that is ideal for this problem that I'm unaware of?
The solution doesn't need to be portable to other database engines... I'm more than happy to use a postgres-only solution.
As far as I can tell, the search filter in the navigator will only search available database names, not table names.
If you click on a table name and start typing, it appears that a simple search can be performed beginning with the first letter of the tables.
I'm looking for way to be able to search all table names in a selected database. Sometimes there can be a lot of tables to sort through. It seems like a feature that would likely be there and I can't find it.
Found out the answer...
If you type for example *.test_table or the schema name instead of the asterisk it will filter them. The key is that the schema/database must be specified in the search query. The asterisk notation works with the table names as well. For example *.*test* will filter any table in any schema with test anywhere in the table name.
You can use the command
SHOW TABLES like '%%';
To have it always in your tools, you can add it as a snippet to SQL aditions panel on the right.
Then you can always either bring it in your editor and type your search key between %%, or just execute it as it is (It will fetch all the tables of the database) and then just filter using the "filter rows" input of the result set.
I'm interested in using the following audit mechanism in an existing PostgreSQL database.
http://wiki.postgresql.org/wiki/Audit_trigger
but, would like (if possible) to make one modification. I would also like to log the primary_key's value where it could be queried later. So, I would like to add a field named something like "record_id" to the "logged_actions" table. The problem is that every table in the existing database has a different primary key fieldname. The good news is that the database has a very consistent naming convention. It's always, _id. So, if a table was named "employee", the primary key is "employee_id".
Is there anyway to do this? basically, I need something like OLD.FieldByName(x) or OLD[x] to get value out of the id field to put into the record_id field in the new audit record.
I do understand that I could just create a separate, custom trigger for each table that I want to keep track of, but it would be nice to have it be generic.
edit: I also understand that the key value does get logged in either the old/new data fields. But, what I would like would be to make querying for the history easier and more efficient. In other words,
select * from audit.logged_actions where table_name = 'xxxx' and record_id = 12345;
another edit: I'm using PostgreSQL 9.1
Thanks!
You didn't mention your version of PostgreSQL, which is very important when writing answers to questions like this.
If you're running PostgreSQL 9.0 or newer (or able to upgrade) you can use this approach as documented by Pavel:
http://okbob.blogspot.com/2009/10/dynamic-access-to-record-fields-in.html
In general, what you want is to reference a dynamically named field in a record-typed PL/PgSQL variable like 'NEW' or 'OLD'. This has historically been annoyingly hard, and is still awkward but is at least possible in 9.0.
Your other alternative - which may be simpler - is to write your audit triggers in plperlu, where dynamic field references are trivial.
I have a large table which inserts data into the database. The problem is when the user edits the table I have to:
run the query
use lots of lines like value="<cfoutput>getData.firstname#</cfoutput> in the input boxes.
Is there a way to bind the form input boxes to the database via a cfc or cfm file?
Many Thanks,
R
Query objects include the columnList, which is a comma-delimited list of returned columns.
If security and readability aren't an issue, you can always loop over this. However, it basically removes your opportunity to do things like locking certain columns, reduces your ability to do any validation, and means you either just label the form boxes with the column names or you find a way to store labels for each column.
You can then do an insert/update/whatever with them.
I don't recommend this, as it would be nearly impossible to secure, but it might get you where you are going.
If you are using CF 9 you can use the ORM (Object Relation Management) functionality (via CFCs)
as described in this online chapter
https://www.packtpub.com/sites/default/files/0249-chapter-4-ORM-Database-Interaction.pdf
(starting on page 6 of the pdf)
Take a look at <cfgrid>, it will be the easiest if you're editing table and it can fire 1 update per row.
For security against XSS, you should use <input value="#xmlFormat(getData.firstname)#">, minimize # of <cfoutput> tags. XmlFormat() not needed if you use <cfinput>.
If you are looking for an easy way to not have to specify all the column names in the insert query cfinsert will try to map all the form names you submit to the database column names.
http://help.adobe.com/en_US/ColdFusion/9.0/CFMLRef/WSc3ff6d0ea77859461172e0811cbec22c24-7c78.html
This is indeed a very good question. I have no doubt that the answers given so far are helpful. I was faced with the same problem, only my table does not have that many fields though.
Per the docs EntityNew() the syntax shows that you can include the data when instantiating the object:
artistObj = entityNew("Artists",{FirstName="Tom",LastName="Ron"});
instead of having to instantiate and then add the data field by field. In my case all I had to do is:
artistObj = entityNew( "Artists", FORM );
EntitySave( artistObj );
ORMFlush();
NOTE
It does appear from your question that you may be running insert or update queries. When using ORM you do not need to do that. But I may be mistaken.
This may be a very simplistic question, so apologies in advance, but I am very new to database usage.
I'd like to have Postgres run its full text search across multiple joined tables. Imagine something like a model User, with related models UserProfile and UserInfo. The search would only be for Users, but would include information from UserProfile and UserInfo.
I'm planning on using a gin index for the search. I'm unclear, however, on whether I'm going to need a separate tsvector column in the User table to hold the aggregated tsvectors from across the tables, and to setup triggers to keep it up to date. Or if it's possible to create an index without a tsvector column that'll keep itself up to date whenever any of the relevant fields in any of the relevant tables change. Also, any tips on the syntax of the command to create all this would be much appreciated as well.
Your best answer is probably to have a separate tsvector column in each table (with an index on, of course). If you aggregate the data up to a shared tsvector, that'll create a lot of updates on that shared one whenever the individual ones update.
You will need one index per table. Then when you query it, obviously you need multiple WHERE clauses, one for each field. PostgreSQL will then automatically figure out which combination of indexes to use to give you the quickest results - likely using bitmap scanning. It will make your queries a little more complex to write (since you need multiple column matching clauses), but that keeps the flexibility to only query some of the fields in the cases where you want.
You cannot create one index that tracks multiple tables. To do that you need the separate tsvector column and triggers on each table to update it.