最近几年来，地理信息系统无论是在理论上还是应用上都处在一个飞速发展的阶段。 GIS被应用于多个领域的建模和决策支持，如城市管理、区划、环境整治等等，地理信息成为信息时代重要的组成部分之一； “数字地球”概念的提出，更进一步推动了作为其技术支撑的GIS的发展。 与此同时，一些学者致力于相关的理论研究，如空间感知、空间数据误差、空间关系的形式化等等。 这恰好说明了地理信息系统作为应用技术和学科的两个方面，并且这两个方面构成了相互促进的发展过程。
We can use SQL to create the query so that we can specify that only the selected records and fields can be viewed. We want to show only records that begin with An in the “Companyname” fieldof the “Customers” table: Display “Companyname” records greater than E How to display only records greater than E in the Companyname field of the Customers table. ` Only display customers in Spain < https://www.runoob.com/try/showasp.php?filename=demo_query_3 >`__How to display only Spanish customers in the “Customers” table. Allow users to choose filtering criteria Let users select customers according to their country Show selected data ¶
<html> <body> <% set conn=Server.CreateObject("ADODB.Connection") conn.Provider="Microsoft.Jet.OLEDB.4.0" conn.Open "c:/webdata/northwind.mdb" set rs=Server.CreateObject("ADODB.recordset") sql="SELECT Companyname, Contactname FROM Customers WHERE CompanyName LIKE 'A%'" rs.Open sql, conn %> <table border="1" width="100%"> <tr> <%for each x in rs.Fields response.write("
" & x.name & "") next%> tr> <%do until rs.EOF%> <tr> <%for each x in rs.Fields%> <td><%Response.Write(x.value)%>td> <%next rs.MoveNext%> tr> <%loop rs.close conn.close%> table> body> html> More Instance ¶