1. 
CREATE TABLE yasai (
  shohin varchar,
  price int
);

\d

INSERT INTO yasai (shohin, price) VALUES ('imo', 100);
INSERT INTO yasai (shohin, price) VALUES ('ninjin', 110);
INSERT INTO yasai (shohin, price) VALUES ('tomato', 390);
SELECT * FROM yasai ;

2.
SELECT * FROM yasai WHERE price > 100;

3.
CREATE TABLE junban (
  code varchar,
  junjo int
);

\copy junban from /pub/eis/postcode/yubinpost.tab

4.
INSERT INTO junban (code, junjo) VALUES ('0420916', 7);

5. 
UPDATE junban SET junjo = 10 WHERE code = '0410802';

6.1.
シェルのコマンド行で (psql を終了して）
less /pub/db/postcode/renshuTable

6.2.
grep 01202 /pub/eis/postcode/renshuTable | awk '{print $1, $3, $8, $9}' > hakodate

6.3.
CREATE TABLE main (
  code varchar,
  zip  varchar,
  city varchar,
  chomei varchar
);

\copy main from hakodate using delimiters ' '

7.
SELECT junban.junjo, main.chomei 
FROM main, junban
WHERE main.zip = junban.code
ORDER BY junban.junjo;