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.

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22
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2answers
1k views

Internal-use websites: Is there a compelling case against SQLite?

Many web frameworks, such as Flask or Django use SQLite as their default database. SQLite is compelling because it's included in python, and administrative overhead is pretty low. However, most high ...
0
votes
1answer
167 views

Search for object in loop or query? Who has better performance?

I have a DB that stores some complex objects of my app. When my app starts I load the objects into list and store them on the RAM. But sometimes I would like to search for an objects that fulfills ...
0
votes
1answer
89 views

Multiple schemas vs aditional column per customer

If you have different database per customer as there is no need to share any data between them does the same apply if a customer has multiple stores ? I believe that it is easier to do queries for ...
0
votes
1answer
101 views

SQL-99 specification, is it specified to first order the result and limit it afterwards?

If I wrote this in MySQL SELECT * FROM foo ORDER BY bar LIMIT 1 it would first order the result and limit it afterwards. I always get the lowest bar. I wonder if this is specified like this in ...
8
votes
1answer
268 views

Can relational algebra/calculus proofs be used to test/verify SQL?

Is it feasible or even possible to use relational algebra and/or relational calculus in the form of proofs to test/verify the correctness of SQL statements, functions, and stored procedures? It seems ...
7
votes
5answers
317 views

In retrospect, has it been a good idea to use three-valued logic for SQL NULL comparisons?

In SQL, NULL means "unknown value". Thus, every comparison with NULL yields NULL (unknown) rather than TRUE or FALSE. From a conceptional point of view, this three-valued logic makes sense. From a ...
13
votes
2answers
3k views

SQLite with two python processes accessing it: one reading, one writing

I'm developing a small system with two components: one polls data from an internet resource and translates it into sql data to persist it locally; the second one reads that sql data from the local ...
18
votes
4answers
2k views

Why many designs ignore normalization in RDBMS?

I got to see many designs that normalization wasn't the first consideration in decision making phase. In many cases those designs included more than 30 columns, and the main approach was "to put ...
5
votes
2answers
363 views

Good architecture for user information on separate databases?

I need to write an API to connect to an existing SQL database. The API will be written in ASP.Net MVC3. The slight problem is that with existing users of the system, they may have a username on ...
10
votes
7answers
447 views

Nested Entities and calculation on leaf entity property - SQL or NoSQL approach

I am working on a hobby project called Menu/Recipe Management. This is how my entities and their relations look like. A Nutrient has properties Code and Value An Ingredient has a collection of ...
1
vote
1answer
219 views

Store data for multiple User Type

I am developing an app where four types of user share same module. So is it a good idea to create: one table and user_type and user_id (something like that) table prefixes basically 4 diff tables of ...
8
votes
1answer
2k views

Is inline SQL still classed as bad practice now that we have Micro ORMs?

This is a bit of an open ended question but I wanted some opinions, as I grew up in a world where inline SQL scripts were the norm, then we were all made very aware of SQL injection based issues, and ...
1
vote
2answers
132 views

Configurable tables in sql database

I have the following tables in my database: Config Table: ====================================== Start_Range | End Range | Config_id 10 | 15 | 1 ...
0
votes
1answer
450 views

Are there any SQL servers that support compiled queries?

Can SQL queries be compiled into byte code or equivalent to enhance performance? I know that most database servers support prepared statements, but is that the same thing as compiling? Most ...
0
votes
2answers
3k views

Using lucene and sql server togheter. Newbie needs directions [closed]

Basically the whole thing can be explained simply: I need to index one or more SQL Server 2005 databases with lucene so I can search the various records. I found a lot of examples and documentation ...
2
votes
1answer
663 views

Status update & news feed database design / architecture

Imagine a application similar to Facebook, where you have status updates and a news feed. The names and profile pictures can be changed. There are also several different types of updates requiring a ...
-1
votes
9answers
332 views

Can you share an explanation or experience that gave you clarity about how to use SQL SELECTS? [closed]

I have been programming for a long time, like 13 years (only professionally for about 4). I've become familiar with things like QBasic, Visual Basic, C#, .NET, Java, C, C++, Javascript, JQuery, etc. I ...
2
votes
4answers
931 views

Database is performing slow, even all the tables are having normalization

One of the interviewers asked me this question: Tables are created with appropriate normalization rules, However the database is performing slow. [Ie.: The select, insert statements are taking ...
0
votes
1answer
881 views

C# Design for SQL connection and commands

Currently I'm working on system that works with database, and I would like to have it done elegant way. So I have abstracted DBConnection into one class, DBCommands into another class. (DBCommands : ...
6
votes
8answers
2k views

Why can't SQL return joined tables in a nested format?

For example, say I want to fetch a User and all of his phone numbers and email addresses. The phone numbers and emails are stored in separate tables, 1-user to many phones/emails. I can do this quite ...
-1
votes
3answers
391 views

What would be a good “umbrella” term for HTML, CSS, SQL, JavaScript and the like? [closed]

There appears to be a pretty clear consensus on the question about whether HTML and CSS are programming languages. They are not. HTML is a markup language and CSS is a stylesheet language. You could ...
3
votes
2answers
918 views

Best practice in application design / SQL authentication

I am currently involved in the implementation/design of an existing application for a large scale customer. The application has a similar model as e.g. vCenter Server whereby a number of components ...
1
vote
2answers
3k views

Using Autoincrement Primary keys as Foreign Keys

When creating a table, there is an option for us to set the numeric primary key as autoincrement where it's value increases whenever a new data in inserted. This primary number can be used for ...
0
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2answers
242 views

Automating database deployment using a CMS

My team are developing Umbraco websites and looking to improve the automation of our database deployment. Currently we have automated builds and deployments of our source code using Kiln and Team ...
3
votes
4answers
928 views

Other things to learn for becoming a Database Admin/Developer?

Obviously i'll have to make some sort of choice at what DB i choose to go with (MS-SQL/MYSQL/etc) but this question isn't about that. The question mainly is what other languages/tools would be ...
4
votes
6answers
1k views

How can I improve upon this “pattern”?

I have a series of method calls that all share similar qualities. The basic layout is public void CallDataBase() { Utility sqlHelper = new Utility(); StringBuilder query = new ...
4
votes
5answers
3k views

SSIS: How long does it usually take to bring a new hire up to speed? [closed]

I’m a self-taught SQL developer that has worked for small to mid-sized companies. Most of my experience has been writing SQL statements for reporting, data scrubs, and never in a formalized IT ...
0
votes
2answers
224 views

Best practices for rotating large datasets?

[edit]Turns out there's 1.5 million records... The SQL database is taking about 17-20 seconds to run the query. Would it be best to have Java handle the joins and rearranging in that case? Since this ...
4
votes
2answers
941 views

Logic design question for SQL query

Was wondering if you could help me on a SQL problem I’m having. I have a set of records of events where each event has a start time and end time. No event has the same start time, and the end time ...
1
vote
1answer
177 views

What's the best approach to building a db schema for profile, but to track changes?

I'm working on a site where companies can create a profile then add locations for each profile. Those first two tables are simple enough. But any changes to their profiles or locations have to go ...
3
votes
5answers
2k views

Is SQLite a sensible option for data logging?

I am trying to setup a small data-logging application under linux. The data arrives via serial port, and from there it should be pumped to logging and to graphical display. The logging functionality ...
0
votes
1answer
365 views

Different ways to generate the latest int type primary foreign key in code

I am new to sql. I have added 2 new tables in database. The primary key of first is a foreign key in the other. The type of the keys is integer. Now I want to generate the keys in the code and assign ...
6
votes
2answers
1k views

In what order are rows fetched absent ORDER BY clause?

One programmer is testing and comparing the same application which uses the same database structure, and the same data, only in two separate databases, one with Oracle 8 and one with Oracle 9. The ...
16
votes
9answers
5k views

Whether to put the business logic in Stored Procedure or Not?

There is always a debate over the topic - "Whether to put the business logic in Stored Procedure or Not?". If we decide not to use the ORM Tool and not to put the Business Logic in Stored Procedure ...
47
votes
14answers
3k views

Is SQL important if I know ORM frameworks well? [closed]

I don't have any serious experience in SQL and I even hate to write SQL instead of LINQ. I am happy enough with ORMs. From the employers and sector view point, is it important to know SQL? Do I have ...
11
votes
5answers
2k views

At what size of data does it become beneficial to move from SQL to NoSQL?

As a relational database programmer (most of the time), I read articles about how relational databases don't scale, and NoSQL solutions such as MongoDB do. As most of the databases I have developed ...
3
votes
1answer
3k views

JOIN vs. INNER JOIN and FULL OUTER JOIN

I know there is a difference between INNER JOIN and FULL OUTER JOIN, I can see it, but, what is the difference between the two following: JOIN ... ON... and INNER JOIN...ON... and still yet ...
3
votes
3answers
478 views

Why should I add CHECK CONSTRAINT?

Following is a table creating script created by Entity Framework using the model shown in http://codereview.stackexchange.com/questions/14077/is-it-proper-tpt-inheritance. In this script, there are ...
19
votes
2answers
4k views

SQL IN() versus OR

I was working with a query I wrote today had to change the code from the WHERE clause to use a IN(list of stuff) filter instead of using something like item_desc = 'item 1' OR item_desc = 'item 2' OR ...
3
votes
1answer
498 views

Rewriting C# Formula Calculations in T-SQL

We have a 3-tier application with a C# client that connects to a C# web service via WCF and requests data from a SQL Server database. One feature in our application is a user-created form app in ...
3
votes
5answers
331 views

Need thoughts on a course curriculum for an entry-level programmer [closed]

Would love to know your thoughts on a curriculum that will be developed for people that want to get started in the programming field. The goal of the course is to help it's students to ensure that ...
1
vote
1answer
171 views

What is better: multiple sql entries or one sql entry with a list field?

Suppose that I have the following logical information: (tag_name, id). For example: (food, 1),(food, 2),(food, 3),(drink, 1),(drink, 2) I'm trying to decide what is the best way to store it in a ...
0
votes
2answers
76 views

Working with data and meta data that are separated on different servers

While developing a product, I've come across a situation where my group wants to store meta data for data entry forms (questions, layout, etc) in a different database then the database where the ...
6
votes
4answers
5k views

C# Minimal SQL Database

I'm working on a small project (not production) where I'm needing to store enough data that something like a CSV would be inefficient to process and an SQL/MySQL server would be too much. Does .Net ...
0
votes
1answer
382 views

Advanced Search Stored procedure

So I am working on an MVC ASP.NET web application which centers around lots of data and data manipulation. PROBLEM OVERVIEW: We have an advanced search with 25 different filter criteria. I am using a ...
14
votes
5answers
2k views

Why is filesystem preferred for logs instead of RDBMS?

Question should be clear from its title. For example Apache saves its access and error logs in files instead of RDBMS no matter on how large or small scale it is being utilized. For RDMS we just have ...
21
votes
2answers
7k views

self referencing tables, good or bad?

Representing geographical locations within an application, the design of the underlying data model suggests two clear options (or maybe more?). One table with a self referencing parent_id column uk - ...
3
votes
0answers
508 views

Clustering Strings on the basis of Common Substrings

I have around 10000+ strings and have to identify and group all the strings which looks similar(I base the similarity on the number of common words between any two give strings). The more number of ...
12
votes
3answers
737 views

Is reliance on parametrized queries the only way to protect against SQL injection?

All I have seen on SQL injection attacks seems to suggest that parametrized queries, particularly ones in stored procedures, are the only way to protect against such attacks. While I was working (back ...
5
votes
5answers
3k views

Two database fields for date and time - should they be merged?

In the following question, field and table names have been changed to protect their identities. If I have two database columns: MONKEY_DATE DATETIME NULL (with data e.g. 2012-05-14 00:00:00.000) ...