Questions tagged [querying]
516 questions
3
votes
2 answers
Double Not Exists SQL Logic Explanation
There are 2 tables, one called drinkers with a column of names, another called frequents which has 2 columns, drinker and bars (that they frequent).
I have a query that answers this statement:
Drinkers who frequent all bars
or wordred…
Chad
- 185
- 1
- 11
3
votes
2 answers
How to join multiple params dynamically for django Q object
I'm trying to implement a search in a django sqlite db.
I get a list of unknown length of params which should all be matched with a 'LIKE'. This means I want all objects that match at least one of the params.
As I can see from the django docs I can…
Igl3
- 4,900
- 5
- 35
- 69
3
votes
1 answer
Querying JSON with JSONPath or SelectTokens? With JSON.NET in C#
I am trying to use the Newtonsoft.Json.Net in c#. The following is part of JSON file that I need to retrieve data out of:
{
"video":{
"local_recording_device":{
"codecs":null
},
…
stopmotion24
- 119
- 2
- 3
- 10
3
votes
3 answers
System.OutOfMemoryException - when Entity Framework is querying a too big data of Varbinary type
I'm trying to query a varbinary column that contain a file (1,2 Gb).
I'm using Entity Framework. See below:
Database to test
CREATE TABLE [dbo].[BIGDATA]
(
[id] [bigint] IDENTITY(1,1) NOT NULL,
[BIGDATA] [varbinary](max) NULL,
…
user3812703
3
votes
4 answers
Check if the event exists before adding it to the Android calender
I have a list of events in my app. A button on the side lets the user add the event date and time to his/her calender. I use a calender intent to redirect the user to the android calender which the corresponding date and time. Now after the user…
TMS
- 1,201
- 1
- 13
- 20
3
votes
2 answers
MongoDB amount of entries
How get amount of entries (in collection), that hold only unique data in certain key?
For example:
{
"_id": ObjectId("4f9d996eba6a7aa62b0005ed"),
"tag": "web"
}
{
"_id": ObjectId("4f9d996eba6a7aa62b0006ed"),
"tag": "net"
}
{
"_id":…
Alexey Tempter
- 31
- 3
3
votes
1 answer
Aggregating multiple queries into one with EF like this?
I am using EF 4.0 POCO in my application. Are there any downsides to retrieving information like this?
Given a customerId and a productId, I would like to apply some business rules that require me to fetch lots teeny pieces of information from the…
Raghu Dodda
- 1,505
- 1
- 21
- 28
2
votes
1 answer
Ontology and the Web
I've been having trouble accessing an ontology that we built here via the web. I've been trying to understand sparql and as far as I can tell there's no real PHP support for ontologies yet. I was wondering if I'm going about this right trying to…
The God Emperor
- 355
- 2
- 6
- 15
2
votes
1 answer
how to imitate Pandas' index-based querying in Polars?
Any idea what I can do to imitate the below pandas code using polars? Polars doesn't have indexes like pandas so I couldn't figure out what I can do .
df = pd.DataFrame(data = ([21,123], [132,412], [23, 43]), columns = ['c1',…
RacGreen1
- 35
- 4
2
votes
2 answers
LIKE with multiple character conditions using percentage
I've got a query that returns the name of a country, where the name must include all of the vowels (a,e,i,o,u).
I'd like to transform this:
SELECT name FROM world
WHERE name LIKE '%a%'
AND name LIKE '%e%'
AND name LIKE '%i%'
AND name LIKE '%o%'
AND…
Kaleko
- 21
- 2
2
votes
1 answer
MySQL query and insertion optimisation with varchar(255) UUIDs
I think this question has been asked in some way shape or form but I couldn't find a question that had asked exactly what I wish to understand so I thought I'd put the question here
Problem statement
I have built a web application with a MySQL…
Prathamesh Datar
- 375
- 1
- 4
- 20
2
votes
1 answer
Pandas DataFrame Query Python
I am trying to query a dataframe for it's values. My data consists of 6 columns G-p1,G-p2,G-c, H-p1,H-p2, H-c. The values for all the columns are either 'left' or 'right' as they stand for whether a parent/child has left or right handed genotype or…
Scott
- 43
- 7
2
votes
3 answers
NHibernate, Sum Query
If i have a simple named query defined, the preforms a count function, on one column:
How do I get the result of a sum or any query…
Dan
- 29,100
- 43
- 148
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2
votes
0 answers
How to query MongoDB with deep and multiple levels
I have the following json as example:
{
"a": {
"b": {
"c": {
"d1": {
"v1": "valv1",
"v2": "valv2"
},
"d2": {
"v1": "valv1",
"v2":…
user10529711
- 49
- 4
2
votes
1 answer
Linq min date max date model querying
I'm unable to find out on how to get the min date and max date from a dictionary collection.
My model class looks like this:
Dictionary> errorList
public class ErrorModel
{
public string Date { get; set; }
public…
Teckniel
- 149
- 1
- 1
- 11