用到的包:xml.dom.minidom 文档

代码托管位置 github-pytools

需求

有一个表,里面数据量比较大,每天一更新,其字段可以通过xml配置文件进行配置,即,可能每次建表的字段不一样。

上游跑时会根据配置从源文件中提取,到入库这一步需要根据配置进行建表。

解决

写了一个简单的xml,配置需要字段及类型

上游读取到对应的数据

入库这一步,先把原表删除,根据配置建新表

XML文件

<?xml version="1.0" encoding="UTF-8"?>
<!-- 表名 ,数据库名   可灵活配置插入哪个库哪个表 -->
<table name="top_query" db_name="evaluting_sys">
<!-- 非业务主键,自增长,可配名,其他 INTEGER UNSIGNED AUTO_INCREMENT  -->
<primary_key>
<name>id</name>
</primary_key>
<!-- 字段开始 -->
<field>
<name>query</name>
<type>varchar(200)</type>
<is_index>false</is_index>
<description>query</description>
</field>
<field>
<name>pv</name>
<type>integer</type>
<is_index>false</is_index>
<description>pv</description>
</field>
<field>
<name>avg_money</name>
<type>integer</type>
<is_index>false</is_index>
<description></description>
</field>
<!-- 字段配置结束 -->
</table>

处理脚本

#!/usr/bin/python
# -*- coding:utf-8 -*-
#author: wklken
#desc: use to read db xml config.
#-----------------------
#2012-02-18 created
#----------------------

import sys,os
from xml.dom import minidom, Node

def read_dbconfig_xml(xml_file_path):
    content = {}

    root = minidom.parse(xml_file_path)
    table = root.getElementsByTagName("table")[0]

    #read dbname and table name.
    table_name = table.getAttribute("name")
    db_name = table.getAttribute("db_name")

    if len(table_name) > 0 and len(db_name) > 0:
        db_sql = "create database if not exists `" + db_name +"`; use " + db_name + ";"
        table_drop_sql = "drop " + table_name + " if exists " + table_name + ";"
        content.update({"db_sql" : db_sql})
        content.update({"table_sql" : table_drop_sql })
    else:
        print "Error:attribute is not define well!  db_name=" + db_name + " ;table_name=" + table_name
        sys.exit(1)
    #print table_name, db_name

    table_create_sql = "create table " + table_name +"("

    #read primary cell
    primary_key = table.getElementsByTagName("primary_key")[0]
    primary_key_name = primary_key.getElementsByTagName("name")[0].childNodes[0].nodeValue

    table_create_sql += primary_key_name + " INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY,"

    #print primary_key.toxml()
    #read ordernary field
    fields = table.getElementsByTagName("field")
    f_index = 0
    for field in fields:
        f_index += 1
        name = field.getElementsByTagName("name")[0].childNodes[0].nodeValue
        type = field.getElementsByTagName("type")[0].childNodes[0].nodeValue
        table_create_sql += name + " " + type
        if f_index != len(fields):
        table_create_sql += ","
        is_index = field.getElementsByTagName("is_index")[0].childNodes[0].nodeValue

    table_create_sql += ");"
    content.update({"table_create_sql" : table_create_sql})
    #character set latin1 collate latin1_danish_ci;
    print content


if __name__ == "__main__":
read_dbconfig_xml(sys.argv[1])

涉及方法

root = minidom.parse(xml_file_path) 获取dom对象

root.getElementsByTagName("table") 根据tag获取节点列表

table.getAttribute("name") 获取属性

primary_key.getElementsByTagName("name")[0].childNodes[0].nodeValue 获取子节点的值(id 得到id)

2012-02-18