【Educoder作业】MySQL开发技巧 - 批量数据入库及检索

这个期末是不是不考？还是更一下啦

T1 MySQL数据库连接

这题没啥好说的，就是每次用$Python$写数据库题的时候必须做的。

# coding=utf-8
import pymysql
def connect():
# 请在下面添加连接数据库的代码，完成相应功能
# ###### Begin ######
    conn =pymysql.connect(host='localhost', user='root',passwd='123123',charset='utf8')
####### End #######
####### 请不要修改以下代码 #######
    return conn.get_host_info()
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T2 数据库与数据表创建

看题面完成操作即可，换行的话是\不是/。

# coding = utf-8

# 连接数据库，建立游标cursor
import pymysql

def create():
    conn = pymysql.connect(host='localhost', user='root', passwd='123123', charset='utf8')
    cursor = conn.cursor()
    # -----------Begin----------
    # 创建enroll数据库
    cursor.execute('create database enroll')
    conn.select_db('enroll')
    # 创建nudt数据表
    cursor.execute('create table nudt(\
                year int,\
                province varchar(100),\
                firstBatch int,\
                gcMax int,\
                gcMin int,\
                gcMean int,\
                xlMax int,\
                xlMin int,\
                xlMean int)')
    # ------------End-----------
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T3 批量数据入库与检索

这个题有说法的，关键在于$year$等关键字的变量类型和$province$不同。一个是$varchar$，其余是$int$。所以在格式化的时候$province$需要格式化成${}^{\prime }\%s^{\prime }$而其余的$int$只需要格式化成$\%s$.

import pymysql

def insert(year,province,firstBatch,gcMax,gcMin,gcMean,xlMax,xlMin,xlMean):
    # print(type(year))
    conn = pymysql.connect(host='localhost', user='root', passwd='123123', charset='utf8')
    cursor = conn.cursor()
    conn.select_db('enroll')
    # -----------Begin----------
    # 请在下面输入插入数据的语句，完成相应功能
    sql = "insert into nudt (year, province, firstBatch, gcmax, gcMin, gcMean, xlMax, xlMin, xlMean) values('%s', '%s', '%s', '%s', '%s', '%s', %s, %s, %s)" % (year, province, firstBatch, gcMax, gcMin, gcMean, xlMax, xlMin, xlMean)
    cursor.execute(sql)
    # ------------End-----------
    
    # 提交数据到数据库
    conn.commit()
    # 关闭数据库连接
    cursor.close() 
    conn.close()

def select():
    conn = pymysql.connect(host='localhost', user='root', passwd='123123', charset='utf8')
    cursor = conn.cursor()
    conn.select_db('enroll')
    # -----------Begin----------
    # 请在下面输入查询数据的语句，完成相应功能
    sql = 'select * from nudt'
    cursor.execute(sql)
    # 请在下面输入获取数据的语句，完成相应功能
    records = cursor.fetchall()
    # ------------End-----------
    for record in records:
        print(record)

    # 关闭数据库连接
    cursor.close() 
    conn.close()
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T4 多表创建与连接查询

在$select$的$from$可以有$tablename$这种格式出现，之后整行语句都可以用$name$来代替$table$。
当然，题面里的自然链接必然是缺东西的。后面需要有$where$来限制条件。

import pymysql

def create(cursor):
    # -----------Begin----------
    # 创建provincialEntryScore表
    sql = 'create table provincialEntryScore(\
                year int,\
                province varchar(100),\
                entryScore int)'
    cursor.execute(sql)
    # 创建nudtTechScore表
    sql = 'create table nudtTechScore(\
                year int,\
                province varchar(100),\
                techMax int,\
                techMin int,\
                techMean int)'
    cursor.execute(sql)
    # 创建nudtMilScore表
    sql = 'create table nudtMilScore(\
                year int,\
                province varchar(100),\
                milMax int,\
                milMin int,\
                milMean int)'
    cursor.execute(sql)
    # ------------End-----------

def insert(cursor,year,province,entryScore,techMax,techMin,techMean,milMax,milMin,milMean):
    # -----------Begin----------
    # 请在下面输入将数据插入provincialEntryScore表中的语句
    sql = "insert into provincialEntryScore(year, Province, entryScore) values(%s, '%s', %s)" %(year, province, entryScore)
    cursor.execute(sql)
    # 请在下面输入将数据插入nudtTechScore表中的语句
    sql = "insert into nudtTechScore(year, province, techMax, techMin, techMean) values(%s, '%s', %s, %s, %s)" % (year, province, techMax, techMin, techMean)
    cursor.execute(sql)
    # 请在下面输入将数据插入nudtMilScore表中的语句
    sql = "insert into nudtMilScore(year, province, milMax, milMin, milMean) values(%s, '%s', %s, %s, %s)" % (year, province, milMax, milMin, milMean)
    cursor.execute(sql)
    # ------------End-----------

def selectAll(cursor):
    # -----------Begin----------
    # 请在下面输入多表直接汇总的语句
    sql = 'select * from provincialEntryScore, nudtTechScore, nudtMilScore'
    cursor.execute(sql)
    records = cursor.fetchall()
    return records
    # ------------End-----------

def selectEqual(cursor):
    # -----------Begin----------
    # 请在下面输入等值连接的语句
    sql = 'select * from %s a, %s b, %s c \
    where a.year = b.year and\
     b.year = c.year and \
     a.province = b.province and \
     b.province = c.province' % ('provincialEntryScore', 'nudtTechScore', 'nudtMilScore')
    cursor.execute(sql)
    records = cursor.fetchall()
    return records
    # ------------End-----------

def selectNatural(cursor):
    # -----------Begin----------
    # 请在下面输入自然连接的语句
    sql = 'select a.year, a.province, a.entryScore, b.techMax, b.techMin, b.techMean, c.milMax, c.milMin, c.milMean from %s a, %s b, %s c where a.year = b.year and b.year = c.year and a.province = b.province and b.province = c.province' %('provincialEntryScore', 'nudtTechScore', 'nudtMilScore')
    cursor.execute(sql)
    records = cursor.fetchall()
    return records
    # ------------End-----------

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