Postgres temporarily function to get a table schema.

Temp Table Schema Fn.sql

CREATE OR REPLACE FUNCTION pg_temp.generate_create_table_statement(p_table_name varchar)
    RETURNS text AS
$BODY$
DECLARE
    v_table_ddl   text;
    column_record record;
BEGIN
    FOR column_record IN
        SELECT
            b.nspname as schema_name,
            b.relname as table_name,
            a.attname as column_name,
            pg_catalog.format_type(a.atttypid, a.atttypmod) as column_type,
            CASE WHEN
                     (SELECT substring(pg_catalog.pg_get_expr(d.adbin, d.adrelid) for 128)
                      FROM pg_catalog.pg_attrdef d
                      WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum AND a.atthasdef) IS NOT NULL THEN
                         'DEFAULT '|| (SELECT substring(pg_catalog.pg_get_expr(d.adbin, d.adrelid) for 128)
                                       FROM pg_catalog.pg_attrdef d
                                       WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum AND a.atthasdef)
                 ELSE
                     ''
                END as column_default_value,
            CASE WHEN a.attnotnull = true THEN
                     'NOT NULL'
                 ELSE
                     'NULL'
                END as column_not_null,
            a.attnum as attnum,
            e.max_attnum as max_attnum
        FROM
            pg_catalog.pg_attribute a
                INNER JOIN
            (SELECT c.oid,
                    n.nspname,
                    c.relname
             FROM pg_catalog.pg_class c
                      LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
             WHERE c.relname ~ ('^('||p_table_name||')$')
               AND pg_catalog.pg_table_is_visible(c.oid)
             ORDER BY 2, 3) b
            ON a.attrelid = b.oid
                INNER JOIN
            (SELECT
                 a.attrelid,
                 max(a.attnum) as max_attnum
             FROM pg_catalog.pg_attribute a
             WHERE a.attnum > 0
               AND NOT a.attisdropped
             GROUP BY a.attrelid) e
            ON a.attrelid=e.attrelid
        WHERE a.attnum > 0
          AND NOT a.attisdropped
        ORDER BY a.attnum
        LOOP
            IF column_record.attnum = 1 THEN
                v_table_ddl:='CREATE TABLE '||column_record.schema_name||'.'||column_record.table_name||' (';
            ELSE
                v_table_ddl:=v_table_ddl||',';
            END IF;

            IF column_record.attnum <= column_record.max_attnum THEN
                v_table_ddl:=v_table_ddl||chr(10)||
                             '    '||column_record.column_name||' '||column_record.column_type||' '||column_record.column_default_value||' '||column_record.column_not_null;
            END IF;
        END LOOP;

    v_table_ddl:=v_table_ddl||');';
    RETURN v_table_ddl;
END;
$BODY$
    LANGUAGE 'plpgsql' COST 100.0 SECURITY INVOKER;

Tks https://stackoverflow.com/questions/2593803/how-to-generate-the-create-table-sql-statement-for-an-existing-table-in-postgr/16154183#16154183