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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1answer
453 views

What happens if computer crashes after giving commit command

If we are updating a field in SQL and ALTER the row also. After giving the COMMIT command, the system is crashed. What will happen to the commands given, whether it will UPDATE and ALTER the table ...
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3answers
240 views

Select custom output formats from database with SQL

I am planning to make a simple rest service application, and I am currently deciding the architecture. I have decided that I want to write the middle layer in multiple languages, so that it is easy to ...
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0answers
108 views

Using a single table for identity and metadata

I'm in the early design phase of a project to provide an e-commerce platform that will require several entities to be modelled, products, customers, orders, CMS pages, etc. They will all have a few ...
3
votes
1answer
215 views

Best way to rename existing unique field names in database?

I have a database table that contains id, filename, userId id is unique identifier filename should also be unique table may contain >10000 records When a user uploads a file it should be ...
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1answer
400 views

Do software developers write SQL? [closed]

Do software developers write SQL or database developers provide the SQL and the software developers use it? I am a novice to software development. I am just trying to understand the software ...
132
votes
13answers
69k views

Why use a database instead of just saving your data to disk?

Instead of a database I just serialize my data to JSON, saving and loading it to disk when necessary. All the data management is made on the program itself, which is faster AND easier than using SQL ...
2
votes
2answers
282 views

Use Of Exists clause in SQL

Just finished Stanford lecture on SQL (by Prof. Jennifer Widom). However I have developed a confusion regarding the use of EXISTS clause. I thought it is just like a condition and an expression so ...
4
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3answers
504 views

Is it better to use a switch statement or database to look through 5,000 to 10,000 instances?

I have some JSON data in this format (5,000 instances for now): {"id":"123456","icon":"icon.png","caseName":"name of case"} I am allowing the user to search for the name of the case and then return ...
4
votes
4answers
735 views

Choosing value in SQL query vs (Java) code

I need to choose one of three values of an integer using the value of a column on a nullable column of a table. There are at least two approaches: 1) use SQL to do all the work: test null values, and ...
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3answers
144 views

High-Level SQL Interoperability

In a server -> client scenario, wouldn't it be simpler and faster to grant a public user access to a Stored Procedure rather than using web services (XML, REST, SOAP, etc) and other interoperable ...
0
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1answer
695 views

How to combine Google Analytics with Relational Database

I have a website with quite a lot of registered users, they are stored in a PostgreSQL database. I also running Google Analytics on the website to track the users. Is there a way to individually ...
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4answers
179 views

When to store Date/DateTime?

I'm working on a social network website and I'm not quite sure when I should store the date/datetime. The service includes some of the following events: Register/Login Follow "Like" (images & ...
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votes
1answer
2k views

Why do we still use a programming language instead of using just SQL? [duplicate]

In database managements systems lecture, my professor said that we can use Oracle etc. ui designing tools instead of using Visual C# or etc. He added that SQL is as strong as a programming language. ...
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0answers
255 views

Match buyers and sellers based on date ranges and quantity of shares

NOTE: This is in reference to the question I asked on Stack Overflow but was told to post this here I'm building a trading application that matches buyers/sellers that own subscription. Subscriptions ...
51
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11answers
66k views

SQL: empty string vs NULL value

I know this subject is a bit controversial and there are a lot of various articles/opinions floating around the internet. Unfortunatelly, most of them assume the person doesn't know what the ...
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1answer
3k views

Size of database a factor for Hibernate vs JDBC?

Do you know if the size of the database (number of tables used) is a factor when choosing between Hibernate and JDBC? Why or why not? In my particular case, I am evaluating Hibernate and JDBC for ...
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5answers
251 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
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2answers
529 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 ...
4
votes
4answers
3k 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
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4answers
717 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
144 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
530 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
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1answer
985 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
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3answers
486 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 ...
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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
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1answer
135 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, ...
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1answer
207 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 ...
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1answer
741 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 ...
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1answer
202 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
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2answers
2k 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 ...
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votes
1answer
363 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
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1answer
96 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
156 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
328 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 ...
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5answers
339 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 ...
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2answers
4k 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
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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 ...
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2answers
394 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 ...
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7answers
632 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 ...
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vote
1answer
333 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 ...
1
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2answers
156 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 ...
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1answer
650 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 ...
2
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1answer
987 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 ...
0
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1answer
1k 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 : ...
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3answers
573 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 ...
4
votes
2answers
1k 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 ...
0
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2answers
378 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
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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
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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 ...
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5answers
4k 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 ...