1、增加

2、增加多條資料

import pymysql
conn = pymysql.connect(
        host="localhost",
        port=3306,
        database="2008a",
        user="root",
        password="123456",
        charset="utf8",
)
cursor = conn.cursor()
# 建立班級的sql語句
sql="insert into student3(id,name,age)VALUES (0,%s,%s)"
data=[("
 
alex1",16),("汙Sir1",17),("xiaoyima1",18)]
try:
    cursor.executemany(sql, data)  # 內部實現for迴圈，批量執行插入語句
    conn.commit()  # 提交一次
except Exception as e:
    print("錯啦！")
    conn.rollback()
cursor.close()
conn.close()

3、刪除

import pymysql
conn = pymysql.connect(
            host="localhost",
            port
 
=3306,
            database="2008a",
            user="root",
            password="123456",
            charset="utf8",
)
cursor = conn.cursor()
# sql = "delete from info WHERE name=%s"
sql = "delete from student3 WHERE id=%s"
cursor.execute(sql,2)
conn.commit()
cursor.close()
conn.close()

4、修改資料

import
 
 pymysql
conn = pymysql.connect(
        host="localhost",
        port=3306,
        database="2008a",
        user="root",
        password="123456",
        charset="utf8",
)
cursor = conn.cursor()
sql = "update student3 set age=%s where name=%s"
cursor.execute(sql,[123, "張三"])
conn.commit()
cursor.close()
conn.close()

5、查詢資料

import pymysql

conn = pymysql.connect(
        host="localhost",
        port=3306,
        database="2008a",
        user="root",
        password="123456",
        charset="utf8",
)

cursor = conn.cursor(cursor=pymysql.cursors.DictCursor)  # 指定返回的資料格式為字典格式

sql = "select * from student3"

cursor.execute(sql)  # 返回的不是具體的資料而是受影響的行數
# ret = cursor.fetchall()  # 返回所有的資料
ret = cursor.fetchone()  # 返回第一條的資料
print(ret)
# ret = cursor.fetchone()  # 接著上一條返回一條資料
# print(ret)

# ret = cursor.fetchmany(3)  # 查詢具體多少條資料，這裡查詢前三條資料
# print(ret)
# # cursor.scroll(0, mode="absolute")  # 絕對移動，寫多少就是移到多少，這裡從第1條資料開始查
# cursor.scroll(-1, mode="relative")   #相對移動，這裡-1表示游標往前移動資料到第2條資料，從第3條資料開始查
# ret = cursor.fetchall()
# print(ret)
cursor.close()
conn.close()