On Wednesday, May 23, 2018, a <372660...@qq.com> wrote: > > How could I select the element of Ay that satisfy x=3?? >
https://www.postgresql.org/docs/10/static/arrays.html#ARRAYS-SEARCHING The note at the end of that section applies here though, you are forcing yourself to fight the nature of the relational database by not normalizing your data model. Converting your array of composites to a table is going to make life considerably easier if you expect to have to performs searches like you requrest help for here. David J.
