Python 操作 MySQL
配置
pip安裝pymysql模塊
直接使用pip安裝 pip install pymysql
win64上直接在cmd中執行
連接本地數據庫
使用模塊pymysql連接數據庫
#!/usr/bin/python# coding=utf-8import pymysql# 連接本地數據庫conn = pymysql.connect(host='localhost', port=3306, user='root', passwd='a123', db='samp_db1', charset='utf8')cursor = conn.cursor()cursor.execute('select * from bigstu')for row in cursor.fetchall(): print(row)# 查cursor.execute('select id, name from bigstu where age > 22')for res in cursor.fetchall(): print(str(res[0]) + ", " + res[1])cursor.close()print('-- end --')輸出：
(1, '張三', '男', 24, datetime.date(2017, 3, 29), '13666665555')(6, '小剛', '男', 23, datetime.date(2017, 3, 11), '778899888')(8, '小霞', '女', 20, datetime.date(2017, 3, 13), '13712345678')(12, '小智', '男', 21, datetime.date(2017, 3, 7), '13787654321')1, 張三6, 小剛-- end --
可以直接執行sql語句。獲得的結果是元組。
增
插入數據
插入一條數據，接上面的代碼
insertSql = "insert into bigstu (name, sex, age, mobile) values ('%s','%s',%d,'%s') "xiuji = ('秀吉', '男', 15, '13400001111')cursor.execute(insertSql % xiuji)conn.commit() # 別忘了提交添加列
在mobile后面添加一列cash
addCo = "alter table bigstu add cash int after mobile"cursor.execute(addCo)
如果要設置默認值
addCo = "alter table bigstu add cash int default 0 after mobile"cursor.execute(addCo)
刪
刪除數據
刪除 name=秀吉 的數據
deleteSql = "delete from bigstu where name = '%s'"cursor.execute(deleteSql % '秀吉')
刪除列
刪除cash列
dropCo = "alter table bigstu drop cash"cursor.execute(dropCo)
改
修改數據
更新符合條件的數據
updateSql = "update bigstu set sex = '%s' where name = '%s'"updateXiuji = ('秀吉', '秀吉') # 秀吉的性別是秀吉cursor.execute(updateSql % updateXiuji)conn.commit()事物處理
給某個記錄的cash增加
table = "bigstu"addCash = "update " + table + " set cash = cash + '%d' where name = '%s'"lucky = (1000, "秀吉")try: cursor.execute(addCash % lucky)except Exception as e: conn.rollback() print("加錢失敗了")else: conn.commit()直接執行SQL語句，十分方便
代碼片段
給數據庫添加列
從json中讀取需要添加的列名，獲取當前2個表中所有的列名
整理得出需要插入的列名，然后將列插入到相應的表中
import pymysqlimport jsonimport osimport secureUtilsmapping_keys = json.load(open("key_mapping_db.json", "r"))db_keys = [] # json中所有的keyfor k in mapping_keys.values(): db_keys.append(k)conn = pymysql.connect(host='localhost', port=3306, user='root', passwd='*****', db='db_name', charset='utf8')cursor = conn.cursor()table_main = "table_main"main_table_keys = [] # 主表的列名cursor.execute("show columns from " + table_main)for row in cursor.fetchall(): main_table_keys.append(row[0])staff_table_keys = []cursor.execute("show columns from table_second")for row in cursor.fetchall(): staff_table_keys.append(row[0])need_to_insert_keys = []for k in db_keys: if k not in staff_table_keys and k not in main_table_keys and k not in need_to_insert_keys: need_to_insert_keys.append(k)print("need to insert " + str(len(need_to_insert_keys)))print(need_to_insert_keys)for kn in need_to_insert_keys: print("add key to db " + kn) cursor.execute("alter table staff_table add " + kn +" text")conn.close()將字段字符改變
這里將main_table_keys中的所有字段改為utf8
# change column character set to utf8for co in main_table_keys: change_sql = "alter table " + table_main + " modify " + co + " text character set utf8" print(change_sql) cursor.execute(change_sql)
以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持VEVB武林網。
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