## 增
sql = 'insert into tablename (code,name) values ({a}, {b}) ;'
cursor.execute(sql)
## 改
sql = 'update tablename set name = {b} WHERE code={b};'
cursor.execute(sql)
## 查
sql = 'select code,name from tablename WHERE code={b};'
cursor.execute(sql)
## 打印所有执行结果
rs=cursor.fetchall()
for r in rs:
print r
## 打印一条数据的所有字段信息
rs=cursor.fetchone()
for r in range(1,n):
print list(rs)[i]