ADO 查询

我们可以使用 SQL 来创建查询，这样就可以指定仅查看选定的记录和字段。

实例

如何仅仅显示 "Customers" 表的 "Companyname" 字段中以 A 开头的记录。

<html>
<body>

<%
set conn=Server.CreateObject("ADODB.Connection")
conn.Provider="Microsoft.Jet.OLEDB.4.0"
conn.Open(Server.Mappath("/db/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("<th>" & x.name & "</th>")
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>

显示 "Companyname" 大于 E 的记录

如何仅仅显示 "Customers" 表的 "Companyname" 字段中大于 E 的记录。

<html>
<body>

<%
set conn=Server.CreateObject("ADODB.Connection")
conn.Provider="Microsoft.Jet.OLEDB.4.0"
conn.Open(Server.Mappath("/db/northwind.mdb"))
set rs = Server.CreateObject("ADODB.recordset")
sql="SELECT Companyname, Contactname FROM Customers WHERE CompanyName>'E'"
rs.Open sql, conn
%>

<table border="1" width="100%">
<tr>
<%for each x in rs.Fields
    response.write("<th>" & x.name & "</th>")
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>

仅显示西班牙的客户

如何仅仅显示 "Customers" 表中的西班牙客户。

<html>
<body>

<%
set conn=Server.CreateObject("ADODB.Connection")
conn.Provider="Microsoft.Jet.OLEDB.4.0"
conn.Open(Server.Mappath("/db/northwind.mdb"))
set rs = Server.CreateObject("ADODB.recordset")
sql="SELECT Companyname, Contactname FROM Customers WHERE Country='China'"
rs.Open sql, conn
%>

<table border="1" width="100%">
<tr>
<%for each x in rs.Fields
    response.write("<th>" & x.name & "</th>")
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>

让用户来选择筛选标准

让用户根据国别来选择客户

<html>
<body>

<%
set conn=Server.CreateObject("ADODB.Connection")
conn.Provider="Microsoft.Jet.OLEDB.4.0"
conn.Open(Server.Mappath("/db/northwind.mdb"))

set rs=Server.CreateObject("ADODB.recordset")
sql="SELECT DISTINCT Country FROM Customers ORDER BY Country"
rs.Open sql,conn

country=request.form("country")

%>

<form method="post">
Choose Country <select name="country">
<%  do until rs.EOF
    response.write("<option")
    if rs.fields("country")=country then
      response.write(" selected")
    end if
    response.write(">")
    response.write(rs.fields("Country"))
    rs.MoveNext
loop
rs.Close
set rs=Nothing %>
</select>
<input type="submit" value="Show customers">
</form>

<%
if country<>"" then
   sql="SELECT Companyname,Contactname,Country FROM Customers WHERE country='" & country & "'"
   set rs=Server.CreateObject("ADODB.Recordset")
   rs.Open sql,conn
%>
   <table width="100%" cellspacing="0" cellpadding="2" border="1">
   <tr>
     <th>Companyname</th>
     <th>Contactname</th>
     <th>Country</th>
   </tr>
<%
do until rs.EOF
   response.write("<tr>")
   response.write("<td>" & rs.fields("companyname") & "</td>")
   response.write("<td>" & rs.fields("contactname") & "</td>")
   response.write("<td>" & rs.fields("country") & "</td>")
   response.write("</tr>")
   rs.MoveNext
loop
rs.close
conn.Close
set rs=Nothing
set conn=Nothing%>
</table>
<%  end if %>

</body>
</html>

显示选定的数据

我们希望仅仅显示 "Customers" 表的 "Companyname" 字段中以 A 开头的记录：

<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("<th>" & x.name & "</th>")
  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>