# 引入模塊
import MySQLdb
# 連接數(shù)據(jù)庫
db = MySQLdb.connect(host="localhost", user="your_username", passwd="your_password", db="your_database")
# 創(chuàng)建cursor對象
cursor = db.cursor()
使用Cursor執(zhí)行SQL語句：創(chuàng)建了cursor對象之后，你可以使用它的execute()方法來執(zhí)行SQL語句。例如，你可以執(zhí)行SELECT查詢來從數(shù)據(jù)庫中檢索數(shù)據(jù)，或者執(zhí)行INSERT、UPDATE、DELETE等語句來修改數(shù)據(jù)。
# 執(zhí)行SQL查詢
cursor.execute("SELECT * FROM your_table")
獲取查詢結(jié)果：如果執(zhí)行的是查詢（如SELECT語句），你可以使用cursor對象的fetchone()、fetchmany()或fetchall()方法來獲取結(jié)果。
# 獲取所有查詢結(jié)果
results = cursor.fetchall()
for row in results:
    print(row)
關(guān)閉Cursor和連接：完成數(shù)據(jù)庫操作后，你應(yīng)該關(guān)閉cursor對象并關(guān)閉數(shù)據(jù)庫連接，以釋放資源。
# 關(guān)閉cursor
cursor.close()
# 關(guān)閉數(shù)據(jù)庫連接
db.close()

cursor.execute("SELECT * FROM your_table")
while True:
    row = cursor.fetchone()
    if row is None:
        break
    print(row)

cursor.execute("SELECT * FROM your_table")
result = cursor.fetchmany(3)  # 獲取3行數(shù)據(jù)
for row in result:
    print(row)

cursor.execute("SELECT * FROM your_table")
results = cursor.fetchall()
for row in results:
    print(row)

import cx_Oracle
# 連接到Oracle數(shù)據(jù)庫
# 方法1: 使用連接字符串
dsn = cx_Oracle.makedsn('hostname', port, service_name='service_name')
connection = cx_Oracle.connect('username', 'password', dsn)
# 方法2: 分別提供連接參數(shù)
# connection = cx_Oracle.connect('username', 'password', 'hostname', port, service_name='service_name')
# 使用cursor執(zhí)行SQL語句
cursor = connection.cursor()
cursor.execute("SELECT * FROM your_table")
# 獲取查詢結(jié)果
results = cursor.fetchall()
for row in results:
    print(row)
# 關(guān)閉cursor和連接
cursor.close()
connection.close()

import pyodbc
# 連接到SQL Server數(shù)據(jù)庫
conn_str = (
    r'DRIVER={ODBC Driver 17 for SQL Server};'
    r'SERVER=your_server_name;'
    r'DATABASE=your_database_name;'
    r'UID=your_username;'
    r'PWD=your_password'
)
conn = pyodbc.connect(conn_str)
# 創(chuàng)建cursor對象
cursor = conn.cursor()
# 執(zhí)行SQL語句
cursor.execute("SELECT * FROM your_table")
# 獲取查詢結(jié)果
results = cursor.fetchall()
for row in results:
    print(row)
# 關(guān)閉cursor和連接
cursor.close()
conn.close()