员工信息管理
简单的员工信息增删改查程序
表信息
1,Alex Li,22,13651054608,IT,2013‐04‐01
2,Jack Wang,28,13451024608,HR,2015‐01‐07
3,Rain Wang,21,13451054608,IT,2017‐04‐01
增加
add staff_table Alex Li,25,134435344,IT,2015-10-29
以phone做唯一键(即不允许表里有手机号重复的情况),staff_id需自增
查询支持三种语法
find name,age from staff_table where age > 22
find * from staff_table where dept = "IT"
find * from staff_table where enroll_date like "2013"
删除指定员工信息纪录
del from staff_table where dept = "IT"
更新记录
update staff_table set dept="Market" where dept = "IT"
update staff_table set age=25 where name = "Alex Li"
流程图
语法分析
def syntax_parser(input_sql):
"""
解析sql语句并执行
:param input_sql:
:return:
"""
# print_log("syntax_parser sql star")
syntax_list ={
'find': syntax_find,
'del': syntax_del,
'add': syntax_add,
'update': syntax_update
}
if input_sql.split()[0] in syntax_list.keys() and 'staff_table' in input_str.split():
if 'where' in input_sql.split():
query_clause, where_clause = input_sql.split("where")
# print_log(query_clause + where_clause)
# 执行where条件
match_data = syntax_where(where_clause.strip())
input_action = query_clause.split()[0]
# 执行不同的action
syntax_list[input_action](match_data, query_clause)
else:
match_data = []
for ind, val in enumerate(STAFF_INFO["id"]):
row = []
for col in COLUMN_NAME:
row.append(STAFF_INFO[col][ind])
match_data.append(row)
syntax_list[input_sql.split()[0]](match_data, input_sql.strip())
else:
print_log("语法错误,find/del/add/updata name,age from [staff_table] [where] age [<,>,=,like][1]", 'error')
where语句分析
def syntax_where(where_clause):
"""
解析where条件
where age > 22
:param where_clause:
:return:
"""
# 操作字符
op_list = [">", "<", "=", "like"]
for op_key in op_list:
if op_key in where_clause:
q_name, q_cond = where_clause.split(op_key)
if q_name.strip() in COLUMN_NAME and q_cond.strip() != "":
match_data = op_compare(q_name.strip(), q_cond.strip(),op_key)
return match_data
else:
if not q_name.strip() in COLUMN_NAME:
error_str = "语法错误,字段%s不存在" % q_name
else:
error_str = "条件值为空"
print_log(error_str, "error")
return False
else:
print_log("语法错误,符号不在[<,>,=,like]中","error")
return False
where 语句的比较运算
def convert_str(f_val, f_cond, f_compare_str):
"""
字符串拼接成条件
:param f_cond:
:param f_val:
:return:
"""
if f_cond.find("'") != -1:
val = "'" + f_val + "'"
elif f_cond.find(""") != -1:
val = """ + f_val + """
else:
val = "'" + f_val + "'"
f_cond = "'" + f_cond + "'"
if f_compare_str == 'in':
# 字符比较"'2015' in '2016-02-01'"
exp_str = "%s%s%s" % (val, f_compare_str, f_cond)
else:
# 字符比较
exp_str = "%s%s%s" % (f_cond, f_compare_str, val)
return exp_str
def op_compare(q_name, q_cond, compare_str):
"""
解析where 语句的操作符
:param q_name:
:param q_cond:
:param compare_str:
:return:
"""
match_data = []
if compare_str == "=":
compare_str = "=="
for ind, val in enumerate(STAFF_INFO[q_name]):
if compare_str != "like" and q_cond.isdigit():
# 数字比较
exp_str = "%d%s%d" % (int(val), compare_str, int(q_cond))
elif compare_str != "like" and not q_cond.isdigit():
# 转换操作符两边字符串
# 把val两边加上'val'或"val" ,与输入字符串比较 'Sales' = 'Sales' or "Sales" = "Sales"
# 字符比较
exp_str = convert_str(val, q_cond, compare_str)
# print_log(exp_str)
else:
# if compare_str = like then compare_str = ' in '
op_str = ' in '
# 字符比较
exp_str = convert_str(val, q_cond, op_str)
# print_log(exp_str)
if eval(exp_str):
row_data = []
for col in COLUMN_NAME:
row_data.append(STAFF_INFO[col][ind])
match_data.append(row_data)
# print(tabulate(match_data, headers=COLUMN_NAME, tablefmt="grid"))
return match_data
解析删除语句
def syntax_del(dataset, query_clause):
"""
解析删除语句
del from staff_table where id=3
:param dataset:
:param query_clause:
:return:
"""
for row in dataset:
staff_id = row[0] # 得到id值
staff_index = STAFF_INFO['id'].index(staff_id) # 得到id值在STAFF_INFO[id]的索引
# print_log(staff_index)
for col in COLUMN_NAME:
STAFF_INFO[col].remove(STAFF_INFO[col][staff_index]) # 修改col_name值
save_db()
print_log("成功删除%s条纪录" % len(dataset))
解析增加语句
def syntax_add(dataset, query_clause):
"""
解析增加语句
add staff_table Alex Li,25,134435344,IT,2015-10-29
:param dataset: dataset = [[1,Alex Li,18,13651054608,开发,2013-04-01]]
:param query_clause:
:return:
"""
# 得到增加的值列表
add_data = [col.strip() for col in query_clause.split("staff_table")[-1].split(',')]
phone_ind = COLUMN_NAME.index("phone") # 得到手机所在列
if len(COLUMN_NAME) - 1 == len(add_data):
# 得到最后一行数据,自增长最后一行数据Id最大
max_id = dataset[-1][0]
# 自增长ID
max_id = int(max_id) + 1
# 把ID插入到第一列
add_data.insert(0,str(max_id))
# 得到手机号
phone_val = add_data[phone_ind]
# 判断手机号是否重复
if not (phone_val in STAFF_INFO["phone"]):
# 把数据插入到STAFF_INFO
for index, col in enumerate(COLUMN_NAME):
STAFF_INFO[col].append(add_data[index])
print(tabulate(STAFF_INFO, headers=COLUMN_NAME))
save_db()
print_log("成功添加1条纪录到staff_table表")
else:
print_log("手机号%s重复" %phone_val ,'error')
else:
print_log("语法错误,列数不对,必须字段%s:"% COLUMN_NAME[1:], "error")
解析修改语句
def syntax_update(dataset, query_clause):
"""
修改语句 update staff_table set age=25 where name='Alex Li'
:param dataset:
:param query_clause:
:return:
"""
if "set" in query_clause:
formula_str = query_clause.split("set")
col_name, new_val = formula_str[-1].strip().split('=')
# print(col_name, new_val)
# STAFF_INFO[col_name]
if new_val.find("'") == 0:
new_val = new_val.replace("'", "")
elif new_val.find(""") == 0:
new_val = new_val.replace(""", "")
for row in dataset:
staff_id = row[0] # 得到id值
staff_index = STAFF_INFO['id'].index(staff_id) # 得到id值在STAFF_INFO[id]的索引
STAFF_INFO[col_name][staff_index] = new_val # 修改col_name值
# print_log(STAFF_INFO)
save_db()
print_log("成功修改了%s条数据!" % len(dataset))
else:
print_log("语法错误,未检测到set", "error")
保存数据
def save_db():
"""
#把修改的数据保存到硬盘上
:return:
"""
f = open("%s.new"%DB_FILE, "w",encoding="utf-8")
# for k in COLUMN_NAME:
# row = []
# row = STAFF_INFO[k]
for ind, val in enumerate(STAFF_INFO["id"]):
row = []
for col in COLUMN_NAME:
row.append(STAFF_INFO[col][ind])
w_data = ",".join(row)
# print_log(w_data)
f.write(w_data+"
")
f.close()
os.remove(DB_FILE)
os.rename("%s.new"%DB_FILE, DB_FILE) # 回写原来的文件
解析查询语句
def syntax_find(dataset, query_clause):
"""
查询语句解析
:param dataset:
:param query_clause:
:return:
"""
query_col = query_clause.split("from")[0][4:].split(',') # 得到name,age
filter_col = [col.strip() for col in query_col] # 去除col中的空格
# print(query_col)
reformat_dataset = []
if '*' in filter_col: # 输出所有列
print(tabulate(dataset, headers=COLUMN_NAME, tablefmt="grid"))
print_log("匹配到%s条数据!" % len(dataset))
else:
for row in dataset: # 筛选列
filter_val = []
for col in filter_col:
index = COLUMN_NAME.index(col)
filter_val.append(row[index])
reformat_dataset.append(filter_val)
print(tabulate(reformat_dataset, headers=COLUMN_NAME, tablefmt="grid"))
print_log("匹配到%s条数据!" % len(reformat_dataset))
主函数
if __name__ == '__main__':
"""
用户信息查询
"""
# 把数据载入内存
STAFF_INFO = load_db()
while True:
input_str = input("[staff db:]").strip()
if not input_str : continue
syntax_parser(input_str)
详细代码
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Time : 2018/3/17 12:27
# @Site :
# @File : staff_info_manage.py
# @Software: PyCharm
"""
简单的员工信息增删改查程序
表信息
1,Alex Li,22,13651054608,IT,2013‐04‐01
2,Jack Wang,28,13451024608,HR,2015‐01‐07
3,Rain Wang,21,13451054608,IT,2017‐04‐01
增加
add staff_table Alex Li,25,134435344,IT,2015-10-29
以phone做唯一键(即不允许表里有手机号重复的情况),staff_id需自增
查询支持三种语法
find name,age from staff_table where age > 22
find * from staff_table where dept = "IT"
find * from staff_table where enroll_date like "2013"
删除指定员工信息纪录
del from staff_table where dept = "IT"
更新记录
update staff_table set dept="Market" where dept = "IT"
update staff_table set age=25 where name = "Alex Li"
"""
from tabulate import tabulate
import os
# 存储信息的文件
DB_FILE = "staff.db"
COLUMN_NAME = ['id', 'name', 'age', 'phone', 'dept', 'enroll_date']
# 打印信息
def print_log(msg, log_type="info"):
if log_type == 'info':
print("