sql常用 语句总结

一，插入一个新字段：ALTER TABLE +表名+ADD  COLUMN(字段名+ 类型)

sql1 = 'ALTER TABLE klkl_4s_shop ADD COLUMN (name_real VARCHAR(100) DEFAULT NULL ,registered_capital VARCHAR(100) DEFAULT NULL,register_time VARCHAR(100) DEFAULT NULL,approved_time VARCHAR(100) DEFAULT NULL,industry_num VARCHAR(100) DEFAULT NULL,company_state VARCHAR(100) DEFAULT NULL,creditcode VARCHAR(100) DEFAULT NULL,organizationcode VARCHAR(100) DEFAULT NULL,capital_real VARCHAR(100) DEFAULT NULL,staff_size VARCHAR(100) DEFAULT NULL,insurance_num VARCHAR(100) DEFAULT NULL,company_type VARCHAR(100) DEFAULT NULL,period VARCHAR(100) DEFAULT NULL,trade VARCHAR(100) DEFAULT NULL,business_adress VARCHAR(100) DEFAULT NULL,bussness_scope VARCHAR(100) DEFAULT NULL)'

二，更新数据： UPDATE +表名+SET +字段 = 值

        sql2 = "UPDATE klkl_Service_shop SET name_real = '{}' ,registered_capital = '{}',industry_num = '{}',company_state = '{}',creditcode = '{}',organizationcode = '{}',capital_real = '{}',staff_size = '{}',insurance_num = '{}',company_type = '{}',trade = '{}',adress = '{}',bussness = '{}'WHERE id = '{}'".format(name_real, registered_capital, industry_num, company_state, creditcode, organizationcode, capital_real,staff_size, insurance_num, company_type, trade, adress, bussness,result[1])

三，插入一条新数据：INSERT INTO +表名 + 字段 + values +值

        sql = 'insert into klkl_4s_shop(city,district,company_name,business,phone,adress) values (%s,%s,%s,%s,%s,%s)'

四：从数据库中获取某一列的值：cursor.fetchmany()

coon = pymysql.connect(host='*****', user='root', password='******', port=****, db='')
#二，创建游标
cursor = coon.cursor()
#三，执行查询语句
cursor.execute('select company_name,id from klkl_4s_shop')
#四，获取查询结果
results= cursor.fetchmany(50)
#打印结果
for result in results:
    print(result[0])
    print(result)
    print(result[1])