Greenplum array merging intersection and row variable column, column variable row function

--1. Using the intersection function between Intersect key word groups create OR REPLACE function Array_intersect (Anyarray, Anyarray)  RETURNS Anyarray as  $$     Select ARRAY (        Select UNNEST ($)        INTERSECT        Select UNNEST ($)); $$ LANGUAGE Sql;select Array_ Intersect (array[1,2,3],array[2,3,4]);--2. Row variable column function Unnestselect UNNEST (array[1,2,3]);--3. column variable function array_agg:create Temporary table temp_test01 asselect Array_agg (c) aggtest from (Values (NULL), (' 1 '), (' 2 '), (' 3 ')) TB (c); Select UNNEST ( aggtest) from Temp_test01;select Array_agg ((ID)) from (Select ID,MD5 (Random ():: Text), Clock_timestamp () from Generate_ Series (1,100) t (ID)) T1;

　　

Greenplum array merging intersection and row variable column, column variable row function