Syntax error when trying to add columns to table in DBeaver (postgresql)
According to Postgres docs the correct syntax is:

ALTER TABLE &lt;your_table&gt;
    ADD COLUMN &lt;column name&gt; &lt;column type&gt;,
    ADD COLUMN &lt;column name&gt; &lt;column type&gt;,
    ADD COLUMN &lt;column name&gt; &lt;column type&gt;;


Have a look at Postgres tutorials on PostgreSQL ADD COLUMN: Add One Or More Columns To a Table.

I've set up a minimal example that reproduces your error:



CREATE TABLE newtable (id int);

ALTER TABLE newtable
    ADD COLUMNS f1 float8, f2 int; 



  ERROR:  syntax error at or near &quot;float8&quot;
  LINE 2:     ADD COLUMNS f1 float8, f2 int;                          ^


ALTER TABLE newtable
    ADD COLUMN f1 float8, f2 int, f3 text;



  ERROR:  syntax error at or near &quot;f2&quot;
  LINE 2:     ADD COLUMN f1 float8, f2 int, f3 text;


Using the correct syntax:



ALTER TABLE newtable
    ADD COLUMN f1 float8,
    ADD COLUMN f2 int,
    ADD COLUMN f3 text;
✓


db&lt;>fiddle here