How to merge all integer arrays from all records into single array in postgres

arrays, postgresql, sql

Solution

You could use `unnest` to open up the arrays and then `array_agg` to put them back together:

select array_agg(c)
from (
  select unnest(column_name)
  from table_name
) as dt(c);

Problem

I have a column which is of type integer array. How can I merge all of them into a single integer array? For example: If I execute query: ``` select column_name from table_name ``` I get result set as: ``` -[RECORD 1]---------- column_name | {1,2,3} -[RECORD 2]---------- column_name | {4,5} ``` How can I get `{1,2,3,4,5}` as final result?

Original source

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