| 摘要 |
PURPOSE: A drainage network database constructing method is provided to simply and easily process drainage network analysis by utilizing hierarchy data technique offered from DBMS. CONSTITUTION: A stream table is generated by using a hierarchical id data type. A hierarchical table is filled by using a hierarchical method. A hierarchical query is performed by using a hierarchical method in order to search for upstream and downstream. A value of the hierarchical id data format shows a location of a tree layer. A hierarchical query is performed through transact-SQL having hierarchical data by using a hierarchical id function. |
