The common misconception on here is that “IT” consists of “help desk” and “sysadmin” and then there is “coding” which is a completely separate thing. I think this stuff stems from people in smaller, mostly Microsoft environments.
Meanwhile there are a vast number of jobs in the IT industry. I'm going to go over the different components of a large enterprise IT department just to give people some more background.
Client Services
A huge number of people on here talk about “help desk” jobs but they really are talking about desktop support jobs since at most smaller companies that's what it really is. The average client services group can roughly be broken down into three components.
Smaller companies are going to combine these roles. If you're really small it might all be mashed together as one person. Or it might be 3 people. Or it could be each of these areas is a manager, with 8 team members
System Administration/Infrastructure/Application Support/etc
There are a ton of names for this stuff and it can be broken down into a ton of different subgroups if the environment gets large enough. Teams can be broken down in many ways but these are all possible jobs
*DBAs: This can also live in other places but these people deal with care and feeding of databases, Oracle and MS SQL and others. This can even be broken down further into infrastructure vs application DBAs
Business Intelligence/Analytics/Reporting/Big Data
There are a million different jobs in this area. This is where data warehousing comes in. This is where tools like Crystal Reports and Cognos and BusinessObjects come in. This pool tends to be people with degrees. Look for a lot of analyst titles here
Various application teams
Sysadmins might set up and configure an ERP system or a CRM system, but there are often whole teams of analysts who then live in those systems.
They might run an HR information system or a decision support system or a enterprise resource planning system. These groups may have dotted line reporting to a business leader despite being inside IT.
PMO
Project management office: Some companies will put all their project managers in this area. Others may embed them in the individual teams. A PM could be located in the PMO or a PM could be embedded in an application team.
Security
These people usually have a bunch of experience in other IT jobs listed above before they end up in this area. Security is not a place you typically start your career. In addition to security engineers you have people working on policy and auditing and all kinds of non-technical but very important positions that are very much part of IT security.
Developers
There may be several teams of developers. Developers can also be embedded in other teams within the IT organization. You'll often find developers on the identity management team. You might need a developer on the CRM team who can do customizations for things the company needs.
Networking
If a company gets big enough this can be divided into multiple groups. You have the telecom people who deal with phones. You have the physical plant people who actually deal with all the cables in the walls. (This could also be outsourced). You also have network technicians who install gear and patch stuff in. You have the network engineers that deal with switching and routing.
Data center
This job can be very physical (racking and HVAC monitoring) or even involve some aspects of network or systems jobs. Totally depends on the company.
There are also a million other jobs I didn't mention.
People get weird about skills on here. Take for instance “coding” which people on here think is somehow some kind of separate thing. Not just developers do this. You might find a network engineer, or a DBA, or a sysadmin on the Exchange team or a identity management person or anyone else writing code.
Who needs to know SQL? business analysts, developers, sysadmins, etc
This is a HUGE field with SOOOO many jobs and the skills are useful on a lot of these.