In a table I store the names of people and I wanted to use a wildcard to check if a part of students name is found. I tried using wild cards and this works if the condition value length is shorter than a value already in the database e.g
WHERE name LIKE '%Stu%'
And I have a person called 'Stuart', this will return a row, however if say I miss type the students name and it is longer than the stored i.e:
WHERE name LIKE '%Stuarfd%'
there I will get no results returned. Is there anyway to match only part of the string?
Have you tried using SOUNDEX?
WHERE SOUNDEX(name) = SOUNDEX('Stuarf')
More info in:
https://www.sqlite.org/lang_corefunc.html#soundex
What you might want is Levenshtein distance, which is also called edit distance. This is the number of edits needed to change one string into another.
SQLite implements this through an extension called Spellfix1, which is available here. The particular function is spellfix1_editdist (). Levenshtein distance is not really so useful for partial matches. The idea is to be able to type in "Stuarf" and find "Stuart", because they are close.
Related
Although I can find solutions to errors caused when a simple text value in a Google query contains an apostrophe, I cannot yet find a solution to when a variable in a Google query might (or might not) refer to a text value that contains an apostrophe.
I am using a simple code to extract a value (column B) related to a list of schools (column A), some of which have apostrophes in their names.
query(SchoolsData_db,"select B where A = '"&$A13&"' label B ''")
For all of the schools with apostrophes I get a #VALUE! error.
I am wondering if there is code I can run against the variable itself ('"&$A13&"') to handle the possible apostrophe. I know I can create a "cleaned name" column corollary to the school names, and then a reverse lookup to restore the names with my results table, but I am hoping the problem can be solved in each calculation instead.
You might try creating a variable first and concatenating that to the query string.
OK - interpreting the suggestion I got, I created and included a text ID column in the schools data (ex: S0001, etc.) and then I used that ID as my variable in the query. All is well. Thanks. I hope others can find this if they are similarly perplexed.
I am writing a python script that gets info from a database through SQL queries. Let's say we have an SQL array with information about some people. I have one query that can retrieve this information about a specific person whose name I pass as an argument to the query.
(" SELECT telephone FROM People_info WHERE name=%s " % (name))
Is it possible to pass as an argument a special character or something like that will return me the telephone for all the names? Meaning something that when I compare with every name the result will be equal? I want to use only one query for all the cases (either if I want the info about one person or all of them)
You can edit the SQL code in
SELECT telephone FROM People_info WHERE name=nvl(%s, name)
and pass null if you want to get all the records
Notice that this will never get the records where name is null, but I suppose this is not a problem.
You can use LIKE and the wild card % which matches no, one or any number of any characters.
SELECT telephone
FROM people_info
WHERE name LIKE '%';
However, it won't show records where name IS NULL.
Maybe the optimizer is smart enough to see, that this actually equivalent to a WHERE name IS NOT NULL and uses an index, if there is one. But maybe it don't see it, then this may come as higher price than necessary. So I'd rather change the WHERE clause (or completely omit it, if I wanted all records) in the application to what I actually want, then use such tricks.
Any one have any pointers how I can store wildcards in a database and the see which row(s) a string matches? Can it be done?
e.g.
DB contains a table like:
So john3136 should get 10 times his regular pay. fred3136 would get half his regular pay.
harry3136 probably crashes the app since there is no matching data ;-)
The code needs to do something like:
foreach(Employee e in all_employees) {
SELECT Multiplier FROM PayScales WHERE
//??? e.Name matches the PayScales.Name wildcard
}
Thanks!
Edit
This is a real world issue: I've got a parameter file that contains wildcards. The code currently iterates through employees, iterates through the param file looking for a match - you can see why I'd like to "databaserize" it ;-)
Wildcards are optional. The row could have said "john3136" to only match one employee. (The real app isn't actually employees, so it does make sense even if it looks like overkill in this simple example)
One option open: I do know all the employee names before I start, so I could iterate through them and effectively expand the wildcards in a temporary table. (so if I have john3136* in the starting table, it might expand to john3136, john31366 etc based on the list of employees). I was hoping to find a better way than this since it requires more maintenance (e.g. if we add functionality to add an employee we need to maintain the expanded wildcards table).
SELECT * FROM payscales
WHERE e.Name
LIKE regexp_replace(name, E'^\\*|\\*$', '%', 'g');
I don't know which database you're using. The above query works on postgresql and just replace your trailing and leading wildcard with %, that's the LIKE wildcard.
If no wildcard is present, it must match the full string.
class A:
name = Char...
class B:
base = ForeignKey(A)
value = Integer..
B.objects.values('a__name','value').distinct('a__name')
As you understand above, I try to get the B objects grouping by its related object's name. However, distinct function doesn't take parameter.
I have tried by annotation and aggregation but I couldn't group by a__name
I have also tried values_list with flat=True but it only takes one column name but I need both a__name and value fields.
How can I do that in Django?
Thanks
First, you need Django 1.4+. If you're running a lesser version, you're out of luck. Then, you must be using PostgreSQL. Passing a parameter to distinct does not work with other databases.
See the documentation for distinct and pay attention to the "Note" lines.
You could always issue a raw query, I suppose, as well, if you don't meet the above conditions.
I am using qodbc (a quickbooks database connector) It uses an ODBC-like sql language.
I would like to find all the records where a field matches a pattern but I have a slight delema.
The information in my field looks like this:
321-......02/25/10
321-1.....02/26/10
321-2.....03/25/10
321-3.....03/26/10
322-......04/25/10
322-1.....04/26/10
322-2.....05/25/10
322-3.....05/26/10
I would like my query to return only the rows where the pattern matches the first number. So if the user searches for '321' it will only show records that look like 321 but not those that have 321-1 or 321-3. Similarly if the user searched for 321-1 you would not see 321. (that's the easy part)
Right now I have
LIKE '321%'
This finds all of them regardless of if they are followed by dots or not. Is there a way I can limit the query to only specifics despite that field having more information that it should.
(P.S. I did not set up this system, it makes me wince to see two data points in one field
I'm sorry if my title isn't right, suggest a new title if you can. )
LIKE '321%' AND NOT LIKE '321-%'