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Requirements
There is a table with a large amount of data, which is updated every day. Its fields can be configured through the xml configuration file, that is, the fields may be different every time the table is created. When running upstream, it will be extracted from the source file according to the configuration. In the step of warehousing, the table needs to be built according to the configuration.
Solution
Write a simple xml, configure the required fields and types to read the corresponding data upstream and put it into the database. First delete the original table and create a new table according to the configuration
XML file
name="top_query" db_name="evaluting_sys"> id query varchar(200) false query pv integer false pv avg_money integer false
Processing script
#!/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])
Involved methods
root = minidom.parse(xml_file_path) Get the dom object
root.getElementsByTagName( "table") Get the node list based on tag
table.getAttribute("name") Get the attribute
primary_key.getElementsByTagName("name")[0].childNodes[0].nodeValue Get the value of the child node (id gets id)
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