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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2
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1answer
288 views

When deciding a Primary Key, can I use Date part of a DateTime field

I'm designing a payroll system I have designed a database with several tables and this question is related to following tables EMPLOYEE (Employee_ID [pk], Name,... etc) LOCATION (Location_ID [pk], ...
1
vote
0answers
79 views

Serialized values or separate table, which is more efficient?

I have a Rails model email_condition_string with a word column in it. Now I have another model called request_creation_email_config with the following columns admin_filter_group:references ...
0
votes
1answer
133 views

Simplifying data search using .NET

An example on the asp.net site has an example of using Linq to create a search feature on a Music album site using MVC. The code looks like this - public ActionResult Index(string movieGenre, string ...
1
vote
1answer
127 views

Dynamic Query Generation : suggestion for better approaches [closed]

I am currently designing a functionality in my Web Application where the verified user of the application can execute queries which he wishes to from the predefined set of queries with where clause ...
56
votes
6answers
3k views

Is this a ridiculous way to structure a DB schema, or am I completely missing something?

I have done a fair bit of work with relational databases, and think I understand the basic concepts of good schema design pretty well. I recently was tasked with taking over a project where the DB was ...
0
votes
2answers
726 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 ...
-3
votes
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 ...
1
vote
3answers
114 views

Store history in SQL database column

We have a database that stores the process/history of particular machines. What I mean by that is that we have "started", "updating", "shutdown", and so on for all the computers in the company. The ...
5
votes
4answers
302 views

Direct database manipulation an anti-pattern?

Recently I learned that some teams have moved all their database manipulation to the actual database through the use of stored procedures. I thought that was pretty clever, since the database becomes ...
9
votes
4answers
3k views

Maintaining referential integrity between a mobile client and a server

So I have a relatively simple system. A mobile client creates records in a sqlite database that I would like to have synced to a remote SQL server (that is shared with other mobile clients). So when I ...
0
votes
0answers
40 views

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 ...
1
vote
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 ...
2
votes
1answer
172 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
votes
0answers
195 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 ...
0
votes
0answers
37 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 ...
3
votes
6answers
3k 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 ...
0
votes
2answers
158 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
0
votes
2answers
103 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 ...
1
vote
1answer
211 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 ...
0
votes
3answers
141 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 ...
82
votes
10answers
11k 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 ...
12
votes
11answers
12k views

Why is prefixing column names considered bad practice?

According to a popular SO post is it considered a bad practice to prefix table names. At my company every column is prefixed by a table name. This is difficult for me to read. I'm not sure the ...
4
votes
6answers
2k views

Confusion about proper use of * wildcard in SQL [duplicate]

Suppose I was writing an address book application where the details of each contact were stored in an SQL database. A user wants to know all the details for a person whose name is "Bob [Someone]". ...
0
votes
4answers
324 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 ...
0
votes
1answer
626 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 ...
1
vote
0answers
140 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 ...
3
votes
5answers
199 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. ...
6
votes
2answers
316 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. ...
104
votes
15answers
14k views

“Never do in code what you can get the SQL server to do well for you” - Is this a recipe for a bad design?

It's an idea I've heard repeated in a handful of places. Some more or less acknowledging that once trying to solve a problem purely in SQL exceeds a certain level of complexity you should indeed be ...
0
votes
0answers
122 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 ...
4
votes
2answers
460 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 ...
0
votes
3answers
103 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 ...
0
votes
1answer
212 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 ...
1
vote
3answers
131 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 ...
0
votes
0answers
39 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
184 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 ...
1
vote
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 ...
116
votes
13answers
44k 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
144 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 ...
3
votes
3answers
421 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 ...
0
votes
0answers
29 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. ...
4
votes
4answers
373 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 ...
0
votes
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 ...
0
votes
1answer
228 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 ...
1
vote
1answer
310 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, ...
0
votes
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 & ...
-4
votes
1answer
1k 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. ...
-2
votes
1answer
106 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 ...
2
votes
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 ...
2
votes
0answers
201 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 ...