PyCharm連接MySQL數據庫，進行創建數據庫實例的創建和表的創建以及表的增刪改查操作

一、創建數據庫實例

from pymysql import *
# 創建數據庫實例
#1.建立數據庫連接
conn  = connect(host="192.168.20.101",user="root",password="123456")
# 2.獲取游標對象
mycur = conn.cursor()
#3.執行創建數據庫實例，並返回int類型結果   1表示添加成功，如果數據庫實例已經存在則拋出異常
try:
    result = mycur.execute("create database pydb")
    print("添加數據庫實例后返回的結果：",result)
except ProgrammingError as msg:
    print("添加數據庫實例出現異常：",msg)
finally:
    #4.關閉游標
    mycur.close()
    # 5.關閉連接
    conn.close()

二、創建表

from pymysql import *
# 1. 創建數據庫連接對象
conn = connect(host="192.168.20.101", user="root", password="123456",database="pydb")
# 2.從連接對象上獲取游標
mycur = conn.cursor()
# 3.執行創建數據庫的表tb_user,返回int類型的結果  成功添加表的話，返回0 ；添加失敗拋出異常
try:
    result = mycur.execute("""
    CREATE TABLE `tb_user` (
      `id` bigint(20) NOT NULL AUTO_INCREMENT,
      `username` varchar(50) NOT NULL COMMENT '用戶名',
      `password` varchar(32) NOT NULL COMMENT '密碼，加密存儲',
      `phone` varchar(20) DEFAULT NULL COMMENT '注冊手機號',
      `email` varchar(50) DEFAULT NULL COMMENT '注冊郵箱',
      `created` datetime NOT NULL,
      `updated` datetime NOT NULL,
      PRIMARY KEY (`id`),
      UNIQUE KEY `username` (`username`) USING BTREE,
      UNIQUE KEY `phone` (`phone`) USING BTREE,
      UNIQUE KEY `email` (`email`) USING BTREE
    ) ENGINE=InnoDB AUTO_INCREMENT=37 DEFAULT CHARSET=utf8 COMMENT='用戶表'
    """)
    print("返回結果：%d"%result)
except (InternalError,ProgrammingError) as msg:
    print("表添加出現異常，異常信息：%s"%msg)
finally:
    # 4關閉游標
    mycur.close()
    # 5 關閉連接
    conn.close()

三、向表中插入數據

from pymysql import  *
# 1.建立到數據庫連接
conn = connect(host="192.168.20.101",user="root",password="123456",database="pydb")
# 2.獲取游標
mycur = conn.cursor()
try:
    # 3.開啟事務
    conn.begin()
    # 4.執行插入數據，並返回影響的行數
    rowNum1 = mycur.execute("""insert into `tb_user` values(1,'lisi','e10adc3949ba59abbe56e057f20f883e','13412345678','[e-mail]','2020-12-25 17:03:55','2020-12-25 17:03:55');""")
    # 防止sql注入的風險，通過%s占位符，
    rowNum2 = mycur.execute("""insert into `tb_user` values(%s,%s,%s,%s,%s,%s,%s);""",
                            (2,'wangwu','202cb962ac59075b964b07152d234b70','13412345679','[e-mail]','2020-12-26 17:03:55','2020-12-26 17:03:55'))
    # 在表名后添加列名
    rowNum3 = mycur.execute("""insert into tb_user(username,password,phone,email,created,updated) values(%s,%s,%s,%s,%s,%s);""",
                            ('zhaoliu','e10adc3949ba59abbe56e057f20f883e','13412345675','[e-mail]','2020-12-27 17:03:55','2020-12-27 17:03:55'))
    row = rowNum1+rowNum2+rowNum3
    print("受影響的行數：",row)
    if row==3:
        #提交事務
        conn.commit()
    else:
        # 回滾事務
        conn.rollback()
except IntegrityError as msg:
    print("出現異常",msg)
    # 回滾事務
    conn.rollback()
finally:
    # 關閉游標
    mycur.close()
    # 關閉連接
    conn.close()

四、查詢表中數據

from pymysql import *
# 建立連接
conn = connect(host="192.168.20.101",user="root",password="123456",database="pydb")
# 獲取游標
mycur = conn.cursor()
# 執行查詢,並返回查詢出來的數據的總行數
rowNum = mycur.execute("select * from tb_user")
print("共查詢出 %d 行數據"%rowNum)
# 獲取查詢出來的數據
results = mycur.fetchall()
print(type(results))
#遍歷輸出
for result in results:
    # print(result)
    print(result[0],result[1])

#關閉游標和連接
mycur.close()
conn.close()

五、修改表中數據

from pymysql import *
conn = connect(host="192.168.20.101",user="root",password="123456",database="pydb")
mycur = conn.cursor()
try:
    conn.begin()
    row = mycur.execute("update tb_user set username=%s,phone=%s,email=%s,updated=%s where id = %s",
                        ('zhaomin','13888889999','[e-mail]','2021-01-29 20:16:20',37))
    # 提交事務
    conn.commit()
    if row ==1:
        print("修改成功")
    else:
        print("修改失敗")
except Exception as msg:
    #回滾事務
    conn.rollback()
    print("修改失敗，提示信息：",msg)
finally:
    # 關閉游標
    mycur.close()
    # 關閉數據庫連接
    conn.close()

六、刪除表中數據

from pymysql import *
# 建立數據庫連接
conn = connect(host="192.168.20.101",user="root",password="123456",database="pydb")
# 獲取游標
mycur = conn.cursor()
try:
    # 開啟事務
    conn.begin()
    # 執行刪除數據
    rowNum = mycur.execute("delete from tb_user where id = %s",(37,))
    print("受影響的行數:",rowNum)
    conn.commit()
except Exception as msg:
    print("刪除拋出異常，提示信息:",msg)
    conn.rollback()#回滾事務
finally:
    # 關閉游標和數據庫連接
    mycur.close()
    conn.close()