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1. CONCAT()??

CONCAT()?????????????????????????CONCAT()????????????

• MySQL/Oracle??? CONCAT(???1, ???2, ...)?
• SQL Server??? + ????

???

• MySQL/Oracle?

  SELECT CONCAT(region_name, store_name) FROM Geography WHERE store_name = 'Boston';

  ???EastBoston

• Oracle?

  SELECT region_name || ' ' || store_name FROM Geography WHERE store_name = 'Boston';

  ???East Boston

• SQL Server?

  SELECT region_name + ' ' + store_name FROM Geography WHERE store_name = 'Boston';

  ???East Boston

2. SUBSTR()??

SUBSTR()??????????????????????????SUBSTR()????????????

• MySQL??? SUBSTR(str, pos) ? SUBSTR(str, pos, len)?
• SQL Server??? SUBSTR(str, pos, len)?

???

• MySQL?

  SELECT SUBSTR(store_name, 3) FROM Geography WHERE store_name = 'Los Angeles';

  ???s Angeles

• SQL Server?

  SELECT SUBSTR(store_name, 2, 4) FROM Geography WHERE store_name = 'San Diego';

  ???an D

3. MINUS??

MINUS???????????????????????

???

SELECT Date FROM Store_Information MINUS SELECT Date FROM Internet_Sales;

???

• Store_Information ???????Jan-05-1999, Jan-08-1999
• Internet_Sales ???????Jan-07-1999

?????Jan-05-1999, Jan-08-1999

MINUS??????????????????????????????????