How to import CSV file data into a PostgreSQL table?

Question

How can I write a stored procedure that imports data from a CSV file and populates the table?

Answer 1

If you need simple mechanism to import from text/parse multiline CSV you could use:

CREATE TABLE t   -- OR INSERT INTO tab(col_names)
AS
SELECT
   t.f[1] AS col1
  ,t.f[2]::int AS col2
  ,t.f[3]::date AS col3
  ,t.f[4] AS col4
FROM (
  SELECT regexp_split_to_array(l, ',') AS f
  FROM regexp_split_to_table(
$$a,1,2016-01-01,bbb
c,2,2018-01-01,ffffd
e,3,2019-01-01,eee$$, '\n') AS l) t;

DBFiddle Demo