PostgreSQL: column names into array PL/pgSQL

问题

create or replace function extr( tabname text ) returns text[] as
$$
declare cols text[];
begin
    execute 'array(select column_name::text from information_schema.columns where table_name = '||quote_literal(tabname)||');' into cols;
    return cols;
end;
$$
language 'plpgsql';

select extr('test');

One supplies a table name and wants back its column-names as an array. The above code gives 'syntax error at or near "array"'. How to fix this?

回答1:

The query should start with select, not array and it doesn't have to be dynamic SQL.

Try this modified version:

create or replace function extr( tabname text ) returns text[] as
$$
declare cols text[];
begin
    select array(select column_name::text from information_schema.columns
      where table_name = tabname) into cols;
    return cols;
end;
$$
language 'plpgsql';

来源：https://stackoverflow.com/questions/32541292/postgresql-column-names-into-array-pl-pgsql