import pymysql

# 數(shù)據(jù)庫相關(guān)信息
dbHost = 'xxxxxxx'
dbUser = 'xxx'
dbPassword = '******'
dbName = 'xxx'
dbCharset = 'utf8'
conn = pymysql.connect(host=dbHost, port=3306, user=dbUser, password=dbPassword, db=dbName, charset=dbCharset)


# 獲取游標對象
cs = conn.cursor()

# 通過游標對象，執(zhí)行sql語句,返回值為受影響記錄的行數(shù)
r = cs.execute('select * from goods')

# 獲取一條數(shù)據(jù)
print(cs.fetchone()) ?# 第一條數(shù)據(jù)
print("==============================================")
# 再次執(zhí)行會獲取第二條數(shù)據(jù)
print(cs.fetchone()) ?# 第二條數(shù)據(jù)

# 獲取多條數(shù)據(jù)
print(cs.fetchmany(3)) ?# 指定條數(shù)

# 獲取全部數(shù)據(jù)
print(cs.fetchall())
# 再次執(zhí)行，獲取到的將是一個空元組，因為上邊的fetchall已經(jīng)取完了（游標可以理解為對獲取位置的標記）
print(cs.fetchall()) ?# 當獲取完畢，再查詢數(shù)據(jù)返回為（）

# 獲取結(jié)束后，要有始有終，關(guān)閉游標和數(shù)據(jù)庫連接
# 關(guān)閉游標
cs.close()
# 關(guān)閉連接
conn.close()

import pymysql
import pandas as pd

# 數(shù)據(jù)庫相關(guān)信息
dbHost = 'xxxxxxx'
dbUser = 'xxx'
dbPassword = '******'
dbName = 'xxx'
dbCharset = 'utf8'
conn = pymysql.connect(host=dbHost, port=3306, user=dbUser, password=dbPassword, db=dbName, charset=dbCharset)

sql = "select xxxxxxxxxxxxxxxxxxxxxxxxxxxx"
df = pd.read_sql(sql, conn)
print(df)

# 關(guān)閉連接
conn.close()