Yes it is as simple as that and light will work but - it will only work from same switch as ceiling light so 2 lights will have to be on together - fine if thats what you want but if you want wall light to be on on its own then you will have to incorporate a switch in circuit.
The most important consideration is, if you are going to run cable down wall to wall light or switch within 50mm of surface, then cables need to be RCD protected to comply with current regs.
This can be done either with RCD fused spur point connected before new wiring or by fitting RCD at source ie at the fuse box which would protect the complete lighting circuit.
Then you will need to test the circuit and the new protection device and issue a certificate to verify compliance.
So what seems to be a simple straightforward job to begin with becomes slightly more complex when the Part P requirements are applied.
Before you start a job like this ask yourself - can I do all that is described above - do I know how to include an RCD into this circuit - have I got the right instruments to test the new circuit before it is energised - have I got the technical know how to be able to issue a certificate?
If answer NO to any of above then dont attempt - consult local electrician.
DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!