Best way to learn SQL from scratch?

[thewanted]

Glad i came across this thread, i need to learn sql for local job vacancies. Looking for the a recognosed qualification (pref 3-6 months)

You didn't think to look on Microsoft's site?

https://www.microsoft.com/en-us/learning/mcsa-sql2016-database-administration-certification.aspx
https://www.microsoft.com/en-us/learning/mcsa-sql2016-database-development-certification.aspx
https://www.microsoft.com/en-us/learning/mcse-data-management-analytics.aspx

 

[samcat]

Which developer edition do you refer to please?

https://www.microsoft.com/en-us/sql-server/sql-server-downloads

Scroll down to developer edition.

Install and setup the test databases, then work your way through W3 schools/khan academy.. Get the basics of selecting, inserting, updating and deleting data... Then learn about joining tables.
https://www.khanacademy.org/computing/computer-programming/sql
https://www.w3schools.com/sql/default.asp

 

[AHarvey]

There aren't any that I'm aware of, SQL is one of those things you go on a week long course for at most and then learn on the job.

Yep, I work in a team of 30 analysts and I don't think any of us have a qualification based around SQL, I knew basic update etc when I started.

 

[morbid42]

There aren't any that I'm aware of, SQL is one of those things you go on a week long course for at most and then learn on the job.

Hmm.. What would my best approach be if i wanted to get to an sql interview? I have a more skilled IT role, fine with data (the output of queries), but all vacancies require a couple of years on the job experience

 

[morbid42]

You didn't think to look on Microsoft's site?

https://www.microsoft.com/en-us/learning/mcsa-sql2016-database-administration-certification.aspx
https://www.microsoft.com/en-us/learning/mcsa-sql2016-database-development-certification.aspx
https://www.microsoft.com/en-us/learning/mcse-data-management-analytics.aspx

Yes have had a look, am wondering whats the best route, want to make sure i do the correct course thats recognised

 

[tom_e]

Hmm.. What would my best approach be if i wanted to get to an sql interview? I have a more skilled IT role, fine with data (the output of queries), but all vacancies require a couple of years on the job experience

Unfortunately if they specify on the job experience then even a recognised qualification probably won't really help as you'll still be lost in the first paper sift.

Can you not try and work it into your current role if you're already working with data? You can use it in things like Excel.

 

[morbid42]

Unfortunately if they specify on the job experience then even a recognised qualification probably won't really help as you'll still be lost in the first paper sift.

Can you not try and work it into your current role if you're already working with data? You can use it in things like Excel.

My current role doesnt have access to what i need. Ive some thinking to do

 

[james.miller]

I've just started learning this in my free time.

I'm starting from scratch and so far, I'm finding this (https://www.udemy.com/the-complete-sql-bootcamp/) course pretty decent.

They often have sales on everything, so keep an eye out and I recently bought the course for £10.

Good old udemy. £10.99 if you dont already have an account, £189.99 if you do lol

 

[AHarvey]

Hmm.. What would my best approach be if i wanted to get to an sql interview? I have a more skilled IT role, fine with data (the output of queries), but all vacancies require a couple of years on the job experience

Where are you located?

 

[morbid42]

Where are you located?

Northern ireland

 

[fretted]

The problem I see with not having experience of SQL work history is that you will be quickly found out with theoretically workable SQL answers that can be found in textbooks but are not always applied in the same way in industry. These are the topics below I think you should understand how they are used in industry first :

* left vs right joins (never use right)
* Union all vs Union joins
* views vs stored procs (answers may vary depending on database)
* reusable user defined functions
* ctes vs tables
* understanding query/execution plans
* using variables and choosing the correct data type
* nulls

I suggest that you at least understand the above fundamentals first and how to write scalable sql solutions before attempting to justify the lack of work history. Nearly all the DB jobs I have been to in the past have questions of performance and best practices where the answer is always 'it depends'

Regards,

 

[morbid42]

The problem I see with not having experience of SQL work history is that you will be quickly found out with theoretically workable SQL answers that can be found in textbooks but are not always applied in the same way in industry. These are the topics below I think you should understand how they are used in industry first :

* left vs right joins (never use right)
* Union all vs Union joins
* views vs stored procs (answers may vary depending on database)
* reusable user defined functions
* ctes vs tables
* understanding query/execution plans
* using variables and choosing the correct data type
* nulls

I suggest that you at least understand the above fundamentals first and how to write scalable sql solutions before attempting to justify the lack of work history. Nearly all the DB jobs I have been to in the past have questions of performance and best practices where the answer is always 'it depends'

Regards,

Thanks for the above information, very useful keywords for me to look into.

I do agree that theory and industry are very rarely synced, for any field

 

[Dolph]

Thanks for the above information, very useful keywords for me to look into.

I do agree that theory and industry are very rarely synced, for any field

I'd also add learning the differences between oltp and olap databases, when they used in industry and why, and make sure you focus on the right type for the type of jobs you are looking for, and start to spread your learnings once you do.

 

[balanceballs]

I would suggest following all the advice in this thread but also, you need to know that in production, most databases are NOT in any way perfect. There will be useless data, there will be tables with no keys, no indexes, no thought about relationships with other tables, incorrect data types, etc. You will find horrible code in stored procedures, badly performing queries, parameter sniffing and many other things that could be avoided if people simply followed best practice and took some time to learn and apply their knowledge. Not to put you off but be aware that most businesses use databases heavily yet employ very little effort in maintaining some form of order. Database analysts (in my experience at several companies) are good at running jobs and occasionally suggesting you add an index, but often fall foul of many things themselves. We're only human but we can do better!

 

[AHarvey]

I would suggest following all the advice in this thread but also, you need to know that in production, most databases are NOT in any way perfect. There will be useless data, there will be tables with no keys, no indexes, no thought about relationships with other tables, incorrect data types, etc. You will find horrible code in stored procedures, badly performing queries, parameter sniffing and many other things that could be avoided if people simply followed best practice and took some time to learn and apply their knowledge. Not to put you off but be aware that most businesses use databases heavily yet employ very little effort in maintaining some form of order. Database analysts (in my experience at several companies) are good at running jobs and occasionally suggesting you add an index, but often fall foul of many things themselves. We're only human but we can do better!

We've just deleted 40 million rows of data from a single table on one of our 60+ clients databases, all useless data

We've had issues with long and short date types as well where a job runs at a set time but was missing the first minute of rows that had been entered due to time issues.

I'd also add learning the differences between oltp and olap databases, when they used in industry and why, and make sure you focus on the right type for the type of jobs you are looking for, and start to spread your learnings once you do.

2 years in a TSQL based analyst role as that's the first time I've heard those terms.

 

[noizeuk]

Thanks for this thread. I was looking for resources to learn SQL as I could do with having more skills when job hunting. What is the normal cost for a microsoft certification? Are there any free certificates?

 

[AHarvey]

Thanks for this thread. I was looking for resources to learn SQL as I could do with having more skills when job hunting. What is the normal cost for a microsoft certification? Are there any free certificates?

Honestly, I work with 30 analysts, none of which have any SQL specific qualifications.

The best thing to do is download some free software such as SSMS, get some sample databases and just start practicing.

You may get an ERD for the database which shows the tables, keys and the relationships between the tables. This will help you when querying multiple tables.

Learn simple selects, joins first. Learn to put things in transactions for anything that makes changes. A transaction makes the change a temp one until you commit it:

BEGIN TRAN

SQL QUERY THAT CHANGES DATA

-- ROLLBACK
-- COMMIT
PRINT @@TRANCOUNT

-- is a comment
rollback will roll back the change you've just made
commit commits the change
the print shows how many open transactions you have open

Personally, we use Transact SQL (TSQL) at work, there's a few different types so worth seeing what's out there.

 

[Deleted member 77746]

I did a little bit of MYSQL, PHPMYADMIN and PHP pulling and pushing data from websites.

I managed to be able to have a webpage, add data, delete it, and modify it.

that was a little project for myself but never implemented anything live.

I used YouTube tutorials to learn.

 

[Sheff]

I've not come across anywhere specifically asking for a certification but a lot of places that ask for experience with SQL will have some sort of test at interview - it's quite easy to get an idea of the candidate's knowledge.

 

[radderfire]

Here are some Microsoft SQL notes.