pymysql

pymysql基本使用

# 導入pymysql模塊
import pymysql
 
# 鏈接database
conn = pymysql.connect(
    host=「你的數據庫地址」, 
    user=「用戶名」,password=「密碼」,
    database=「數據庫名」,
    charset=「utf8」)
 
# 獲得一個能夠執行SQL語句的光標對象
cursor = conn.cursor()  # 執行完畢返回的結果集默認以元組顯示
# 獲得一個能夠執行SQL語句而且將結果做爲字典返回的遊標
#cursor = conn.cursor(cursor=pymysql.cursors.DictCursor)
 
# 定義要執行的SQL語句
sql = """
CREATE TABLE USER1 (
id INT auto_increment PRIMARY KEY ,
name CHAR(10) NOT NULL UNIQUE,
age TINYINT NOT NULL
)ENGINE=innodb DEFAULT CHARSET=utf8;  #注意：charset='utf8' 不能寫成utf-8
"""
 
# 執行SQL語句
cursor.execute(sql)
 
# 關閉光標對象
cursor.close()
 
# 關閉數據庫鏈接
conn.close()

 

插入單條數據

import pymysql
conn =pymysql.connect(
    host ='192.168.0.103',
    port = 3306,
    user = 'root',
    password ='123',
    database ='xing',
    charset ='utf8'
)
cursor =conn.cursor()  #獲取一個光標
sql ='insert into userinfo (user,pwd) values (%s,%s);'
 
name = 'wuli'
pwd = '123456789'
cursor.execute(sql, [name, pwd])
conn.commit()
cursor.close()
conn.close()

 

添加多條數據

import pymysql
 
conn = pymysql.connect(
    host='192.168.0.103',
    port=3306,
    user='root',
    password='123',
    database='xing',
    charset='utf8'
)
# 獲取一個光標
cursor = conn.cursor()
 
# 定義要執行的sql語句
sql = 'insert into userinfo(user,pwd) values(%s,%s);'
data = [
    ('july', '147'),
    ('june', '258'),
    ('marin', '369')
]
# 拼接並執行sql語句
cursor.executemany(sql, data)
 
# 涉及寫操做要注意提交
conn.commit()
 
# 關閉鏈接
cursor.close()
conn.close()

 

獲取最新插入數據 （最後一條）

import pymysql
 
# 創建鏈接
conn = pymysql.connect(
    host="192.168.0.103",
    port=3306,
    user="root",
    password="123",
    database="xing",
    charset="utf8"
)
# 獲取一個光標
cursor = conn.cursor()
# 定義將要執行的SQL語句
sql = "insert into userinfo (user, pwd) values (%s, %s);"
name = "wuli"
pwd = "123456789"
# 並執行SQL語句
cursor.execute(sql, [name, pwd])
# 涉及寫操做注意要提交
conn.commit()
# 關閉鏈接
 
# 獲取最新的那一條數據的ID
last_id = cursor.lastrowid
print("最後一條數據的ID是:", last_id)
 
cursor.close()
conn.close()

 

刪除操做

import pymysql
 
# 創建鏈接
conn = pymysql.connect(
    host="192.168.0.103",
    port=3306,
    user="root",
    password="123",
    database="xing",
    charset="utf8"
)
# 獲取一個光標
cursor = conn.cursor()
# 定義將要執行的SQL語句
sql = "delete from userinfo where user=%s;"
name = "june"
# 拼接並執行SQL語句
cursor.execute(sql, [name])
# 涉及寫操做注意要提交
conn.commit()
# 關閉鏈接
 
cursor.close()
conn.close()

 

查詢數據

import pymysql
 
conn = pymysql.connect (
    host='192.168.0.103',
    port=3306,
    user='root',
    password='123',
    database='xing',
    charset='utf8'
)
# 獲取一個光標
cursor = conn.cursor(cursor=pymysql.cursors.DictCursor)  # 返回字典數據類型
 
# 定義將要執行的sql語句
sql = 'select user,pwd from userinfo;'
# 拼接並執行sql語句
cursor.execute(sql)
 
# 取到查詢結果
ret1 = cursor.fetchone()  # 取一條
ret2 = cursor.fetchmany(3)  # 取三條
ret3 = cursor.fetchone()  # 取一條
 
cursor.close()
conn.close()
 
print(ret1)
print(ret2)
print(ret3)　　

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# 能夠獲取指定數量的數據
cursor.fetchmany(3)
# 光標按絕對位置移動1
cursor.scroll(1, mode="absolute")
# 光標按照相對位置(當前位置)移動1
cursor.scroll(1, mode="relative")

 

數據回滾

import pymysql
 
# 創建鏈接
conn = pymysql.connect(
    host="192.168.0.103",
    port=3306,
    user="root",
    password="123",
    database="xing",
    charset="utf8"
)
# 獲取一個光標
cursor = conn.cursor()
# 定義將要執行的SQL語句
sql1 = "insert into userinfo (user, pwd) values (%s, %s);"
sql2 = "insert into hobby (id, hobby) values (%s,%s);"
user = "july1"
pwd = "july1"
id = "我是錯誤的id"  #id = "3"
hobby = "打遊戲"
try:
    # 拼接並執行SQL語句
    cursor.execute(sql1, [user, pwd])
    print(sql1)
    cursor.execute(sql2, [id, hobby])  # 報錯的SQL語句
    # 涉及寫操做注意要提交
    conn.commit()
except Exception as e:
    print(str(e))
    # 有異常就回滾
    conn.rollback()
 
# 關閉鏈接
cursor.close()
conn.close()

 

參考資料

http://www.javashuo.com/article/p-eaxthkex-bb.html