Python 操作 MySQL資料庫
阿新 • • 發佈:2020-09-24
開發環境與配置
- win_x64
- Ubuntu14.04
- Python3.x
pip安裝pymysql模組
直接使用pip安裝 pip install pymysql
win64上直接在cmd中執行
連線本地資料庫
使用模組pymysql
連線資料庫
本地資料庫相關配置請參閱: http://rustfisher.github.io/2017/02/25/backend/MySQL_install/
#!/usr/bin/python # coding=utf-8 import pymysql # 連線本地資料庫 conn = pymysql.connect(host='localhost',port=3306,user='root',passwd='yourpwd',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',23,11),'778899888')
(8,'小霞','女',20,13),'13712345678')
(12,'小智',21,7),'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。
sql相似條件查詢
SELECT * FROM anindex.subject_basic_table where season_id having '2018';
增
插入資料
插入一條資料,接上面的程式碼
insertSql = "insert into bigstu (name,sex,age,mobile) values ('%s','%s',%d,'%s') " xiuji = ('秀吉',15,'13400001111') cursor.execute(insertSql % xiuji) conn.commit() # 別忘了提交
新增列
在mobile後面新增一列cash
addCo = "alter table bigstu add cash int after mobile" cursor.execute(addCo)
如果要設定預設值
addCo = "alter table bigstu add cash int default 0 after mobile" cursor.execute(addCo)
刪
刪除資料
刪除 name=秀吉 的資料
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
修改資料
更新符合條件的資料
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
程式碼片段
給資料庫新增列
從json中讀取需要新增的列名,獲取當前2個表中所有的列名
整理得出需要插入的列名,然後將列插入到相應的表中
import pymysql import json import os import secureUtils mapping_keys = json.load(open("key_mapping_db.json","r")) db_keys = [] # json中所有的key for k in mapping_keys.values(): db_keys.append(k) conn = pymysql.connect(host='localhost',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()
將欄位字元改變
這裡將main_table_keys中的所有欄位改為utf8
# change column character set to utf8 for co in main_table_keys: change_sql = "alter table " + table_main + " modify " + co + " text character set utf8" print(change_sql) cursor.execute(change_sql)
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