basic knowledge

• 这是什么?

这是一个sql 执行中间件, 它可以从配置文件中读取,并加载配置按需生成相应的sql 并执行.

• 怎么配置

以 xmlFactory 举例.
xml 的文件格式如下
	<DV>
		<ID>1</ID> #dv_id
		<TableName>order_head</TableName>  # the table you will select from 
		<TopRecord>500</TopRecord> # euqal to select top 
		<Fields> # format will be {TrueField} as {DispField}, ${number} is a placeholder number will be replace by true table name
			<Field>
				<DispField>Order_date</DispField> 
				<TrueField>dbo.Fn_DispDateTime($0.Order_date)</TrueField>
				<WhereField>$0.Order_date</WhereField>
			</Field>
                </Fields>
		<Tables>
			<Table ID="88"> # $88
				<Name>V_Type</Name> # true table name
				<Alias>Tp_order</Alias> 
				<Relation> # relations that about with this alias
                                $0.Order_type=$88.Type_no    and  $88.Type_for='Order_type'  and   $88.Pj_id=$0.Pj_id and $88.Status&gt;=0

</Relation>
				<JoinType>left</JoinType>
                        </Table>
                </Tables>
        </Dv>

1 how to use

        engine = create_engine(self.G2CN_str)
        session = sessionmaker(bind=engine)

        factory = XMLFactory("D:\\chenchu\\Python\\DvManager\\test.xml")
        dvm = factory.Build()

        dvm.addQueryField(['Cust_no', 'Order_type_name', 'Order_date'])
        # dvm.filter= DvFilter('Order_date').Equal_to('2019-10-11') #'Order_date'
        dvm.filter.field_name = 'Order_date'
        dvm.filter.LESS_THAN('2019-10-11')

        # add field
        dvm.fields['Pj_id'] = DvField(id="",disp_name='Pj_id',true_name="$0.Pj_id",where_name="$0.Pj_id") 

        pj_id  = DvFilter('Pj_id').Equal_to('82187')

        dvm.filter.AND(pj_id)
        dvm.top_record = 1000
        dvm.temp_tablename = "#ls"

        dvm.sql_adapter = sql_server(session()) # 或许可以设为 default
        print(dvm.Build()) 
        rows = dvm.Query()
        for row in rows:
            print(row)

2.how to load from xml

        factory = XMLFactory("./test.xml")
        dvm = factory.Build()

3.how to generate a xml from a dvid

        # self.AmimanagerDB == connection string
        tools = dv2xml.dv2xml(self.AmimanagerDB,1)
        tools.run("./test.xml")