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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Track time spent on site

We are going to track user engagement (i.e. time spent on site, most viewed part/page of the system, etc). I don't see Google Analytics / MixPanel being able to do this, since we have to analyze ...
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2answers
243 views

Can I create a query which allows me to do this?

I have a table which stores user information, one column stores their ID. I had implemented four different attributes in the same table which stored a bit indicating which file operations that user ...
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3answers
1k views

How to not let anyone inspect elements of a webpage?

I was thinking to make some jQuery functions that will use ajax to control mysql. The whole idea is to make separate files of PHP (e.g query.php, addRow.php, update.php and delete.php) provide data to ...
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2answers
771 views

Large MySQL Batch Inserts From PHP: Run insert from script, or save as SQL file?

We have a large dataset that's current residing in many, many spreadsheets. I've been tasked with getting part of that data into our MySQL DB. When all is said and done, I will probably be inserting ...
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1answer
163 views

MongoDB: Replicate data in documents vs. “join”

Disclaimer: This is a question derived from this one. What do you think about the following example of use case? I have a table containing orders. These orders has a lot of related information ...
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1answer
188 views

Implementing Syncing between localStorage and SQL database?

I have made a simple web app, which runs completely offline - all data is saved in HTML5's localStorage. Now, I want the data to get synced with the server, so that the user is able to use the app on ...
2
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0answers
200 views

Is database version control practical? [closed]

The topic of database version control seems to come up at my work and in social discussion more and more often. But the truth is, I haven't met anyone actually DOING it. The only thing Googling the ...
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0answers
38 views

Charts, SQL and REST?

We have created a REST API for a voting game. Now we are jumping into creating analytics/graphs/charts for moderators and users to watch how are they doing in the game. The game has a certain group ...
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2answers
161 views

When do you use subquery in SQL? [closed]

When do you use subquery in SQL, and what type of request is subquery useful for? I am practicing SQL and need to know how to spot a subquery problem immediately
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6answers
4k views

Using a relational database vs JSON objects for event/activity data

I am working on a project where I am trying to decide between using a standard SQL relational database or JSON objects to store data about an event or activity. The project will store data on ...
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2answers
105 views

Return multiple columns with SQL where GroupBy is on one column [closed]

I have noticed that all the columns in a SQL Select Query should be in a aggregate function, because otherwise the output value for group would be arbitrary. This makes sense. But when the other ...
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1answer
216 views

Is there a purely SQL alternate to looping?

Historically, I probably would have written a script (php or something) to loop through all spreadsheet rows and perform some calculations. I'm looking for a pure SQL solution on the presumption ...
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3answers
147 views

Maintaining indices for location in a sorted list in database rows

I have a fairly simple data structure like this: create table project (id int auto increment primary key, name text); create table item (id int auto increment primary key, name text, project_id ...
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10answers
12k views

Why is “Select * from table” considered bad practice

Yesterday I was discussing with a "hobby" programmer (I myself am a professional programmer). We came across some of his work, and he said he always queries all columns in his database (even on/in ...
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4answers
339 views

How to handle or prevent all Admins and users being removed

I have a website that stores all users in a database. A user can log on to the website and if they have sufficient privileges can add/delete users, as well as change their privileges. How do I ensure ...
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1answer
734 views

Why doesn't MySQL have an explicit “No Limit” option for queries?

I use SQLyog Community edition and like many other SQL applications out there it puts a 1000 result limit on queries that do not have a limit provided. I am wondering why MySQL doesn't have an ...
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5answers
206 views

Is it bad software design to mix JDBC SQL calls and use an ORM in an application? [closed]

Is it bad software design to have JDBC/raw SQL and also use an ORM? I don't mind using an ORM for boilerplate CRUD, but some queries are better in SQL (for me). I'm not arguing for or against ORMs. ...
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2answers
328 views

Slight extension for SQL prepared statements syntax. Need advice

In my database abstraction library I am extending SQL prepared statements syntax to hint a parser with expected literal type. I take it as a very essential improvement, my reasoning you can read here. ...
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2answers
494 views

How deeply programmer should know about internals of database engine? [closed]

I am learning SQL Server 2012 along with C#. In the past, I took database class in college, and have good grasp on SQL language and can write queries. However, looking at SQL Server documentation (or ...
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1answer
605 views

How to translate SQL query into REST API requests?

Let's say I have a machine-readable description (such as in WADL, Swagger or RAML) of a REST API that provides interface to a database. My users submit queries about underlying database in form of ...
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3answers
104 views

SQL string field lengths in a db having about 6 different types of addresses, with about 20 markets and environments

I have been advocating lately that all string fields should be ntext / nvarchar(max) - we're using MS SQL Server. The objections seem to be either "it's not a good idea" (without any reason) or "that ...
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1answer
219 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
134 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
42 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 ...
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1answer
370 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 ...
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2answers
148 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 ...
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134 views

what should I save in local android DB to be more efficient and to last more than one session (and shouldn't be stored in the server only)?

I write an android app. The user sends the server its location and get places relevant to him. He then can up-vote or down-vote any offer. I wonder if I should write to local DB and when? I ...
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0answers
32 views

database design for Media company in SQL 2008

I have to make the report for one of the client. There are three sources from I will get all raw data, so eventually I will have to marry those all data from different sources and make one report. ...
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3answers
424 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 ...
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4answers
385 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
135 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 ...
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1answer
248 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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1answer
311 views

Creating a online database creator

I've been thinking of creating an online database creator (think DabbleDB, Zoho Creator, Intuit Quickbase, etc.). I've been thinking of a couple solutions: Have 4 database tables: Tables, Rows, ...
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4answers
141 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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1answer
122 views

Mental schema for SQL queries

While preparing SQL introductory material, I've ended asking myself about the line of thought followed by a developer when writing a query. I believe it could be too valuable from a beginner's point ...
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1answer
110 views

Finding next free IP in a network

I have an IP network and want to automatically find a free IP address to provision a new server. Due to frequent server additions/removals the used IPs might be quite fragmented over the whole address ...
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0answers
204 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 ...
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5answers
243 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 ...
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2answers
480 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 ...
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2answers
663 views

Database Context and Singleton injection with IoC

All of the below relates to a ASP.NET c# app. I have a Singleton Settings MemoryCache that reads values from database on first access and caches these, then invalidates them using SQL Service Broker ...
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0answers
146 views

What database structure is suitable for tracking File audits?

I need to track permissions and access requests to a file server in a database. I'm given the full path of the folder and am considering parsing the path (splitting on the "/" character) and creating ...
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2answers
131 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
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3answers
303 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 ...
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1answer
330 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
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1answer
109 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
138 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
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 ...
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1answer
150 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 ...
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3answers
469 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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1answer
87 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 ...