Structured Query Language (SQL) is a language for managing data in relational database management systems. This tag is for general SQL programming questions; it is not for Microsoft SQL Server (for this, use the sql-server tag), nor does it refer to specific dialects of SQL on its own.
1
vote
1answer
34 views
Is using triggers best solution for this scenario
A large SQL transactional database has more than 100 tables (and it will grow). One of them is called Order. Then, there is another table WorkLoad which derives from Order and many other joined table ...
6
votes
6answers
140 views
How would you design a user database with custom fields
This question is around how should I design a database, it can be relational / nosql databases, depending on what will be the better solution
Given a requirement where you'll need to create a ...
0
votes
1answer
47 views
Always set form input max length?
Background
I'm looking to put together a single page web application with many form inputs. I've run into issues with other web pages where there is an ugly SQL error sent to the user if the ...
-1
votes
0answers
33 views
SQL combined SELECT statement (for SQL zoo) [migrated]
I was using SQL zoo for brushing up my SQL knowledge and found the following problem:
"Some countries have populations more than three times that of any of
their neighbours (in the same ...
0
votes
0answers
46 views
SQL: GROUP BY where a column is unique [migrated]
So I have this one giant table e.g.
PROD_IDGEOG_IDTIME_IDVALUE1
1 MT JAN 100
...
0
votes
1answer
157 views
Injectable, Poppable Stack
Background
A project involves converting a relational expression map (rxm) to an XML/SQL statement. The map resembles:
root > people, # "root" keyword starts the document
...
0
votes
0answers
11 views
How to use an Address Gazatteer in an application that contains addresses
Say I had access to the post office address file (http://en.wikipedia.org/wiki/Postcode_Address_File) and wanted to cleanse about one million addresses. I am trying to think of an "algorithm" to do ...
5
votes
3answers
223 views
SQL - Algorithm for finding availability of a resource
I'm having trouble creating a mysql compatible algorithm for this.
Background
App with mysql, perl and JS. It's a booking system where each booking is comprised of a start, end and qty. Start and ...
0
votes
0answers
37 views
Preserving Pre-formatted Multi-Line Strings in Node.js Scripts
There is a lot I don't like about PHP, but one thing I love is multi-line strings:
$query = <<<EOT
select
field1
,field2
,field3
from tableName
where
field1 = 123
EOT;
...
1
vote
0answers
138 views
What is the “correct” way to store functions in a database?
Note: Yes, I know that storing functions in databases should be punishable by law.
We are developing a financial web application using PostgreSQL, Sinatra and AngularJS. As you may have guessed, a ...
3
votes
2answers
62 views
Integration tests of SQL logic
In my daily work, I use a lot of SQL logic (oracle stored procedures and SQL functions).
To limit the code regression on the implemented code I make what I call "integration scripts" : C# scripts that ...
3
votes
2answers
78 views
Use of NOLOCK on Microsoft SQL Server
The (NOLOCK) optimizer hint is well known by most SQL developers for setting the isolation level so that tables with rows or escalated page locks can be read. I've always known about the bad and ugly; ...
3
votes
1answer
208 views
Is a series of OR or a single IN SQL statement better?
I'm using MS SQL 2008 R2. I have been using a series of OR and have an issue where my app periodically give the following error:
Exception message: Timeout expired. The timeout period elapsed prior ...
-1
votes
0answers
17 views
SQL divide two columns [migrated]
Let the following cinema database where a user may critic a movie and assign a score from 0 to 10 to his critic :
MOVIE (idMovie)
PK (idMovie)
CRITICS (idMovie, user, score)
PK (idMovie, user)
...
1
vote
2answers
130 views
How should I compare two database tables - with SQL or using Java? [closed]
I have two tables with different structure. I should compare ID from 1st table with ID of the intermediate table and then comapre TXT field of the intermediate table with TXT field of the 2nd table.
...
3
votes
2answers
174 views
Software development - The industry & general trends / Bad practices [duplicate]
I am a Web Developer and part of a small team working on an abundance of projects. This is my first "actual" real company after graduating with a degree in computer Science and I have about 2 years ...
0
votes
1answer
30 views
Merging user activities into one stream with a common representation
My social network website currently has
forum threads and posts
gallery pictures
albums on the users' profiles
group discussions
classifieds
I would like to create one "stream" of activity. It ...
3
votes
2answers
1k views
One of my team members committed SQL injection-vulnerable code; should I report it to the manager? [closed]
One of my team members committed a huge mistake; a clear SQL injection-vulnerability. It obviously didn't pass my peer review and I made very clear that this is unacceptable. I never saw this ...
0
votes
3answers
249 views
Using SQL queries in loops
Is it a bad idea? I need to compare each entry.Key value in a Dictionary of strings to a SQL table. If there is a match, then I pull the data from that row.
I was originally going to use a foreach ...
32
votes
10answers
3k views
Is there any material difference between queries joined by WHERE clauses, and queries using an actual JOIN?
In Learn SQL the Hard Way (exercise six), the author presents the following query:
SELECT pet.id, pet.name, pet.age, pet.dead
FROM pet, person_pet, person
WHERE
pet.id = person_pet.pet_id ...
-1
votes
2answers
116 views
Storing Dates & Times in SQL [closed]
I have a tool that I am working on which allows people to create meetings. They can select the Date, Time & Timezone that this meeting is occurring in.
I need to determine the best way to store ...
2
votes
1answer
166 views
Should I use foreign keys in my database if I use laravel?
I'm creating a website with Laravel for the first time. I checked relationships documentation today and it seems that Laravel just uses simple SQL queries.
class User extends Eloquent {
public ...
3
votes
3answers
367 views
What kind of user info is ok to be stored as plain text in SQL Database?
I'm practicing around building e-commerce asp.net applications that allows for users to register to the site and their user credentials are stored in a MySQL database. In my sample project the ...
0
votes
2answers
498 views
Clients connect to WCF or SQL Server
I was wondering what is the prefered way of accessing data from a server in a client application. The data will be stored on the server in an SQL database and I have previously used the following 2 ...
1
vote
1answer
123 views
Implementing “Trending Items” using linear regression in SQL Server
I'm building an MVC .NET website where people can rate and review movies (similar to IMDb). I'm using SQL Server for the back-end.
I'll be implementing a feature where the homepage displays trending ...
0
votes
2answers
79 views
Sending a notification to each participant 3 hours before the meeting starts
Let's assume an application that deals with meetings where some users will participate.
What is an efficient way to achieve this use case:
3 hours before the meeting should start, one reminder mail ...
3
votes
1answer
150 views
What is the best way to format complex SQL queries in Node?
I am using node-mysql to query a MySQL database via Express and Node. My queries are getting fairly complex and I want to format them across multiple lines. However, the only way I could accomplish ...
10
votes
4answers
818 views
Historical precedent for why Prolog is less popular than SQL in Imperative Programming? [closed]
It seems that writing Declarative SQL is very popular in Imperative Programming. However, it also seems that writing Declarative Prolog could save a lot of complexity but this is not very common.
...
3
votes
3answers
359 views
ASP.NET MVC should I reference the DAL from the UI?
I am developing an ASP.NET MVC application, and I have three projects:
UI (with the system.web.mvc reference, BL and DAL references)
BL (business facade and business objects)
DAL (contains my ...
0
votes
1answer
41 views
Django Project Logic Solution
I'm starting to develop my first webapp, and I'm using django.
Before anything I'm working on the software logic, how it should work, the links and objects it needs.
The problem is:
I need the app ...
2
votes
5answers
193 views
Stored Procedures, ORMs and other application layers
I'm just starting out on a project to develop a new, fairly substantial web application which has an underlying MSSQL database. We're hiring a team of developers to write the application (in .NET) and ...
2
votes
2answers
202 views
An algorithm that spreads similar items across a list
I need an algorithm that distributes same items across a list, so maximizing the distance between occurrences.
E.g.
I have a list of 15 items:
{a,b,c,c,c,d,e,f,f,f,g,h,h,i,j}
The algorithm should ...
31
votes
3answers
1k views
Why is most SQL written in YELLING? [duplicate]
On MySQL at least, the following two queries are functionally identical:
select * from users limit 0, 1000;
SELECT * FROM users LIMIT 0, 1000;
However, most example sites and most developers I've ...
0
votes
2answers
58 views
Efficient database access for related data
As an example for this question, consider a content management system that has a content database table which contains things like the page title and location as well as the content itself which could ...
1
vote
3answers
283 views
Best OOP pattern to use for creating a commandline SQL API for a proprietary json based company datastore
We need to create a SQL commandline tool for querying a proprietary json based datastore. I'll be using java. Any suggestions on the primary OOP design pattern I should use for building this API?
...
-1
votes
1answer
472 views
SQLDatabase: Read a lot of data at once and process in memory or read the data when I need it?
I'm not sure how to approach this problem.
I require a big chunk of data records from the SQL server. This chunk is based on variables, so I don't know before what records I need.
I need to do a large ...
1
vote
1answer
98 views
Database choice [closed]
I am working on a system where I am replacing and existing Cobol system with C#.
For the database I have hit some requirement which I am having a hard time to find complete support for (tried SQLite ...
3
votes
3answers
221 views
Is there a 'standard' SQL that can replace all the various custom versions?
I have been writing SQL for over 10 years now. I am extremely proficient at it and have experience working in SQL Server, Oracle, MySQL, PostgreSQL, etc. While there are multiple standards out there, ...
2
votes
2answers
131 views
Combine union with distinct
Situation: I need distinct results from two tables, that both have duplicates.
I would like to know if I should combine UNION and DISTINCT.
Example 1 - Only use distinct
SELECT DistinctValue
FROM ...
15
votes
4answers
4k views
Databases: Where should the application logic run? [duplicate]
http://highscalability.com/blog/2010/11/9/facebook-uses-non-stored-procedures-to-update-social-graphs.html talks about how Facebook moved logic out of the database into the application in order to ...
4
votes
4answers
398 views
Organise C++ classes around SQL database
My question is about how best to organize C++ classes around a database
model, and I understand this may appear very elementary.
The software I propose to create will do the following. It is intended ...
0
votes
0answers
61 views
An algorithm to implement SQL's ORDER BY with TOP/LIMIT or OFFSET/FETCH
Is there a general algorithm to implement SQL's ORDER BY with OFFSET/LIMIT more efficiently than sorting all the records?
The algorithm for a simple TOP x is easy enough. It takes one full pass ...
1
vote
0answers
228 views
Separation of concerns between repository and service in DDD with complex entities
This probably seems as an example of opinion-based question, but I'm actually looking for rationale on how to decide correctly, I believe there is a correct solution that can be backed by solid ...
3
votes
2answers
272 views
Does ODBC require any run-time software beyond an .exe file to run against MySQL and ORACLE SQL? [closed]
I'm writing a software [under Windows] in C++ which later needs to be able to connect to both MySQL and ORACLE SQL. Now the software needs to be as simple for the user as possible.
Now I'm ...
0
votes
0answers
46 views
Database conceptual Question [duplicate]
When querying in database through PHP, is it good to open mysql connection before every query and close it as the query completes? or should we open the mysql connection as soon as the first query ...
0
votes
0answers
59 views
embedding LEFT OUTER JOIN within INNER JOIN
I am having some problems with one of the question's answered in the book "SQL FOR MERE MORTALS".
Here is the problem statement
Here is the Database Structure
Here is the answer which I am ...
0
votes
2answers
165 views
Is it a bad practice to keep database schema scripts (DDL) and manipulation (DML) scripts in different modules
we have a project structure like the following
"module-shared" module depends on "module-database" module and some other modules depend on "module-shared" but no other module depends on ...
4
votes
2answers
324 views
Entity Framework with no direct table access
There are some similar questions I've found here, but none of them fully answer the question I'm asking. Similar questions: here and here
In my company, I develop C# .NET applications and our Server ...
1
vote
1answer
277 views
Should ORM data access methods be wrapped or used directly?
We're using an internally-built ORM. Each table is represented by a Model class, which inherits from a base model class that has a handful of methods like GetAll, GetWhere (to get rows with specified ...
-4
votes
1answer
95 views
what data storage method should I use? [closed]
I am currently writing a program and among other things need to store data.
The program listens to two computers talking to each other in a known protocol (the program know what protocol it is,the ...
