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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3
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5answers
246 views

Violating SQL principles

I have to write a decent size database, 1GB more or less. I have only taken an introductory semester regarding SQL databases. During the course we learned that the relational model under SQL has no ...
-1
votes
2answers
502 views

Lead developer unable to do INNER JOIN [closed]

I had worked in the past for a small company developing web applications. Back then the current lead developer, who is also one of the bosses, told me that he is incapable of making a JOIN inside a ...
37
votes
11answers
2k views

Why don't relational databases support returning information in a nested format?

Suppose I'm building a blog that I want to have posts and comments. So I create two tables, a 'posts' table with an autoincrementing integer 'id' column, and a 'comments' table that has a foreign key ...
28
votes
7answers
46k views

How do I make complex SQL queries easier to write?

I'm finding it very difficult to write complex SQL queries involving joins across many (at least 3-4) tables and involving several nested conditions. The queries I'm being asked to write are easily ...
4
votes
4answers
2k views

Can NoSQL databases be used in e-commerce companies for order management?

Is it possible to use a non relational database be in an Order management system for an e-commerce company with a large number of orders everyday, like Amazon? Can the benefits of Non Relational ...
2
votes
4answers
526 views

How to genericize foreign key references in table?

I am trying to design a table to store references to multiple tables as a "target" of the item in each row. An example should clarify what I am trying to do: Imagine you have 4 tables (images, ...
2
votes
2answers
136 views

SQL Query syntax - formatting?

I'm looking at a very large (5-6 digit LOC), very complex, code-base, full of interacting bulky, interdependent, views and stored procedures (multiple 4-5 digit count silos). The source SQL has been ...
4
votes
3answers
380 views

How to avoid unmaintainable code when using SQL in an MVC setting?

I want to present a list of products to the user. This list is paginated and can be sorted by the user by product ID or product name in ascending or descending order. I am using an MVC setting, where ...
0
votes
1answer
716 views

Notify client about changes in database in java

I've been searching around for the answer to this question, but haven't been able to find a solution. I am working on a distributed client-server system that uses TCP. The program's functions is to ...
5
votes
3answers
475 views

Consequences of “naïve” vs “naive”?

While using IE autocorrect "naive" got transformed to "naïve"! My regional settings are Au English, from a Unicode search point of view the two are nothing alike. I am not even sure whether there are ...
16
votes
2answers
2k views

Does F# offer anything particularly useful for database-driven web development?

My organization finally upgraded to MS Visual Studio 2010 this year. One of the big new features that Visual Studio 2010 offers is the F# programming language. I understand that F# offers a ...
1
vote
1answer
129 views

structure problem in Relational DBMS creation

For learning and understanding purpose, I currently want to try to make a small relational DBMS with simple features like (for now) only sequential reading/writing and CREATE TABLE, INSERT, SELECT, ...
0
votes
1answer
133 views

How to store Status for Reservation table

I have a reservation table (a user fills out a form to request a reservation). It has two parts that need to be confirmed. isReservationAccepted (decline,accept,waiting) and hasReservationBeenSent ...
0
votes
1answer
524 views

How exactly can I check for new rows in sql with ajax? [closed]

How do certain services, just like google plus and facebook, check for new content without reloading the page? Whenever you are on any of those websites a new notification of a post related content ...
0
votes
1answer
164 views

Queries in three tier architecture

I am wondering where should the DB queries need to be in the three tier architecture. The first association that think is in the DAL. But then if the BL want to search for an object, the DAL need to ...
22
votes
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
200 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
91 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
111 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
275 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
318 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
370 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
481 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
239 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 ...
9
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
138 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
481 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
729 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 ...
2
votes
4answers
1k 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
985 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 : ...
-1
votes
3answers
424 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
982 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
votes
2answers
269 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
1k 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
234 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
996 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
183 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 ...
4
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
396 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 ...
17
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 ...
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
503 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 ...