1.安裝pymysql:pip install pymysql (在命令行窗口中執(zhí)行)
2.卸載pymysql:pip uninstall pymysql (在命令行窗口中執(zhí)行)
需要注意的是port是不用引號括起來 charset是utf8不是utf-8
# 獲取數(shù)據(jù)庫連接對象 connection = pymysql.connect(host='localhost', port=3306, user='root', passwd='2732195202', db='book', charset='utf8') # 獲取一個游標 driver = connection.cursor() # 執(zhí)行一條sql driver.execute("select version()") # 獲取執(zhí)行sql的返回值 resultData=driver.fetchall() print(resultData) # 關(guān)閉數(shù)據(jù)庫 connection.close()
import pymysql #獲取數(shù)據(jù)庫連接對象 connection = pymysql.connect(host='localhost', port=3306, user='root', passwd='2732195202', db='book', charset='utf8') #獲取一個游標 driver=connection.cursor() # 如果該數(shù)據(jù)庫存在就刪除 driver.execute("drop table if exists t_emp ") # 定義sql語句 sql=""" CREATE TABLE `t_emp` ( `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '主鍵', `department` varchar(20) DEFAULT NULL COMMENT '部門', `salary` decimal(10,2) DEFAULT NULL COMMENT '工資', `age` int(11) DEFAULT NULL COMMENT '年齡', `sex` varchar(4) DEFAULT NULL COMMENT '性別', PRIMARY KEY (`id`) )ENGINE=InnoDB DEFAULT CHARSET=utf8; """ # 執(zhí)行sql driver.execute(sql) # 關(guān)閉數(shù)據(jù)連接 connection.close()
1.需要注意的是規(guī)范sql,該寫的字段都寫上,不使用默認對應(yīng)
2.提交事務(wù)的對象是數(shù)據(jù)庫連接對象,而不是游標對象
3.pycharm連接mysql數(shù)據(jù)時,如果連接驅(qū)動是高版本,需要加上時區(qū),jdbc:mysql://localhost/book?serverTimezone=GMT%2B8
4.如果主鍵是自動遞增,則不能手動指定值,不能寫該字段,讓其自增長
# 獲取數(shù)據(jù)庫連接對象 connection=pymysql.connect(host='localhost',port=3306,user='root',passwd='2732195202',db='book',charset='utf8') # 獲取一個游標 driver=connection.cursor() # 定義sql語句 sql=""" insert into t_emp(name,department,salary,age,sex) values("tom","開發(fā)部",8000,25,"男"), ("tom","開發(fā)部",8000,25,"男") """ # 嘗試捕捉錯誤 try: # 執(zhí)行SQL,并返回收影響行數(shù) result=driver.execute(sql) # 提交事務(wù) connection.commit() print("sql(insert)->error") except: # 如果發(fā)生錯誤 則回滾事務(wù) print("sql(insert)->error") driver.rollback() # 關(guān)閉數(shù)據(jù)庫連接 connection.close()
注意點:在操作數(shù)據(jù)庫之前,需要確認是否獲取連接數(shù)據(jù)庫成功,并且選中了數(shù)庫
2.卸載第三方庫:pip uninstall pymysql
#獲取數(shù)據(jù)庫連接對象 autocommit=True:設(shè)置數(shù)據(jù)庫自動提交 connection=pymysql.connect(host="localhost",port=3306,user='root',passwd='2732195202',db='book',charset='utf8',autocommit=True) # 獲取游標對象 driver=connection.cursor() # 定義sql sql="update t_emp set salary=%s,name=%s where id=%s;" # 如果sql錯誤就執(zhí)行回滾操作,成功就提交 try: # 執(zhí)行sql,并且返回影響的行數(shù) result=driver.execute(sql,[6000,"admin",19]) connection.commit() print("sql(update)->success") except: print("sql(update)->error") connection.rollback() # 關(guān)閉數(shù)據(jù)庫連接對象 connection.close()
1.項目中的.py文件不能和python庫中的文件進行沖突,否則會出現(xiàn)異常
# 獲取數(shù)據(jù)庫連接對象 connection=pymysql.connect(host='localhost',port=3306,user='root',passwd='2732195202',db='book',charset='utf8') # 獲取一個游標對象 driver=connection.cursor() #定義sql sql="select id, name, department, salary, age, sex from t_emp where id>%s and sex=%s" # 只能獲取一次,獲取多次的時候會獲取到null 如果是多個參數(shù),需要傳遞一個元組 try: driver.execute(sql,(1,"女")) # 獲取所有的查詢結(jié)果 返回一個元組 resultAll=driver.fetchall() print("resultAll:", resultAll) # 獲取2條數(shù)據(jù) resultTwo=driver.fetchmany(2) print("resultTwo:", resultTwo) # 獲取一條數(shù)據(jù) resultOne=driver.fetchone() print("resultThree:", resultOne) print("sql(select)->success") except: connection.rollback() print("sql(select)->error") # 關(guān)閉數(shù)據(jù)庫連接 connection.close()
import pymysql # 獲取數(shù)據(jù)庫連接對象 connection = pymysql.connect(host='localhost', port=3306, user='root', passwd='2732195202', db='book', charset='utf8') # 獲取一個游標 driver = connection.cursor() # 定義sql sql="delete from t_emp where id=%s" try: # 執(zhí)行一條sql driver.execute(sql, (21)) # 提交事務(wù) connection.commit() print("sql(delete)->success") except Exception as e: # 回滾事務(wù) connection.rollback() print("sql(delete)->error") print(e) #關(guān)閉數(shù)據(jù)庫連接 connection.close()
提交事務(wù): connection.commit()
回滾事務(wù): connection.rollback()
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