《SQL必知必会》—— 操作数据

插入数据

-- 插入完整行
INSERT INTO customers(cust_id, cust_name, cust_address, cust_city, cust_state, cust_zip, cust_country, cust_contact, cust_email) 
VALUES('1000000006', 'Toy Land', '123 Any Street', 'New York', 'NY', '11111', 'USA', NULL, NULL);
-- 插入部分行(省略列为NULL或默认值)
INSERT INTO customers(cust_id, cust_name, cust_address, cust_city, cust_state, cust_zip, cust_country) 
VALUES('1000000006', 'Toy Land', '123 Any Street', 'New York', 'NY', '11111', 'USA');
-- 插入检索出的数据(INSERT SELECT)
INSERT INTO customers(cust_id, cust_name, cust_address, cust_city, cust_state, cust_zip, cust_country)
SELECT cust_id, cust_name, cust_address, cust_city, cust_state, cust_zip, cust_country FROM customersnew;
-- 从一个表复制到另一个表
CREATE TABLE custcopy AS SELECT * FROM customers;

更新数据

UPDATE customers SET cust_email = 'kim@thetoystore.com' WHERE cust_id = '1000000005';
UPDATE customers SET cust_email = NULL WHERE cust_id = '1000000005';    -- NULL删除某个列的值

删除数据

DELETE FROM customers WHERE cust_id = '1000000011';     -- 删除指定行
TRUNCATE TABLE custcopy;                                -- 删除所有行

创建表

CREATE TABLE Products
(
  prod_id    char(10)      NOT NULL , PRIMARY KEY
  vend_id    char(10)      NOT NULL ,
  prod_name  char(255)     NOT NULL ,
  prod_price decimal(8,2)  NOT NULL DEFAULT 0.00 ,
  prod_desc  text          NULL 
);

更新表

ALTER TABLE vendors ADD vend_phone CHAR(20) DEFAULT '000000';   -- 添加vend_phone列，并设置默认值
ALTER TABLE vendors DROP COLUMN vend_phone;                     -- 删除vend_phone列

删除表

DROP TABLE custcopy;