In this contribution we review some of the most relevant results of the PhD thesis awarded with the XIV SEA PhD prize in 2018. The thesis is aimed at characterising the ionised gas abundance distribution in spiral galaxies by using two sets of high-quality integral field spectroscopic data from the CALIFA and AMUSING surveys. We observe that, together with the well-known radial negative gradient, a significant number of galaxies also display a drop in the abundances towards the inner parts of the discs and a flattening in the outermost regions. This suggests that the widely accepted scenario in which the oxygen abundance distribution of spiral galaxies is well described by a single radial negative gradient might be incomplete and deviations from it are needed for a proper characterisation of the distribution. In addition, in the particular case of the galaxy NGC 6754, we perform an analysis of its azimuthal abundance and velocity-residual distributions. This galaxy shows, for the first time, clear signatures of ongoing gas radial migration affecting the abundance distribution. The results obtained in this thesis provide strong constraints to chemical evolution models aimed at explaining the formation and evolution of spiral galaxies, trying to do our bit in the comprehension of the Universe around us.