Questions tagged [sql]
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.
777 questions
243votes
17answers
105kviews
Is it good practice to always have an autoincrement integer primary key?
In my databases, I tend to get into the habit of having an auto-incrementing integer primary key with the name id for every table I make so that I have a unique lookup for any particular row. Is this ...
- 3,028
241votes
13answers
195kviews
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 ...
- 5,850
229votes
19answers
151kviews
Why is naming a table's Primary Key column "Id" considered bad practice? [closed]
My t-sql teacher told us that naming our PK column "Id" is considered bad practice without any further explanations. Why is naming a table PK column "Id" is considered bad practice?
218votes
14answers
109kviews
"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 ...
162votes
4answers
114kviews
why are noSQL databases more scalable than SQL?
Recently I read a lot about noSQL DBMSs. I understand CAP theorem, ACID rules, BASE rules and the basic theory. But didn't find any resources on why is noSQL scalable more easily than RDBMS (e.g. in ...
- 1,739
128votes
14answers
43kviews
Is there any technical reason why, in programming, the default date format is YYYYMMDD and not something else?
Is there any engineering reason why is it like that? I was wondering in the case of a RDBMS that it had something to do with performance, since a "YEAR" is more specific than a "MONTH", for instance: ...
- 1,387
102votes
10answers
56kviews
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 ...
- 1,131
101votes
9answers
27kviews
Is it ever okay to use lists in a relational database?
I've been trying to design a database to go with a project concept and ran into what seems like a hotly debated issue. I've read a few articles and some Stack Overflow answers that state it's ...
- 951
100votes
14answers
44kviews
Is it considered an anti pattern to write SQL in the source code?
Is it considered an anti pattern to hardcode SQL into an application like this: public List<int> getPersonIDs() { List<int> listPersonIDs = new List<int>(); using (...
- 7,139
82votes
12answers
149kviews
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 ...
- 2,264
74votes
6answers
12kviews
Why is the Select before the From in an SQL query? [closed]
This is something that bothered me a lot at school. Five years ago, when I learned SQL, I always wondered why we first specify the fields we want and then where we want them from. According to my ...
- 1,346
63votes
15answers
6kviews
Co-worker renamed all of my queries [closed]
I don't know if I should be very irritated or what. I single handedly built over 300 queries for a large database, and developed a naming convention so I could find them later. No one else in my ...
62votes
6answers
4kviews
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 ...
- 1,997
60votes
16answers
14kviews
Why did SQL injection prevention mechanism evolve into the direction of using parameterized queries?
The way I see it, SQL injection attacks can be prevented by: Carefully screening, filtering, encoding input (before insertion into SQL) Using prepared statements / parameterized queries I suppose that ...
- 8,257
59votes
4answers
62kviews
Why is SQL's BETWEEN inclusive rather than half-open?
Semi-open (or Half-Open, Half-Closed, Half-Bounded) intervals ([a,b), where xbelongs to the interval iff a <= x < b) are pretty common on programming, as they have many convenient properties. ...
- 2,914
