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我有一个网页有以下字段提供搜索工具
name,address,post
三个textboxes.I要提供搜索工具的用户user.if只需输入姓名和点击搜索应该只能由搜索名称,如果用户输入所有文本框的值,它应该用全部3个值来查询数据库。就像明智的我该如何为所有搜索可能性编写sql查询?
我有一个网页有以下字段提供搜索工具
name,address,post
三个textboxes.I要提供搜索工具的用户user.if只需输入姓名和点击搜索应该只能由搜索名称,如果用户输入所有文本框的值,它应该用全部3个值来查询数据库。就像明智的我该如何为所有搜索可能性编写sql查询?
select *
from Table1
where
(coalesce(@Name, '') = '' or Name = @Name) and
(coalesce(@Address, '') = '' or Address = @Address) and
(coalesce(@Post, '') = '' or Post = @Post)
我更喜欢这个查询选项。如果用户仅在其中一个字段中输入值,则将空值传递给其他各个字段的参数。
Create PROCEDURE [dbo].[uspGetPeople]
@name varchar(50),
@Address varchar(200),
@Post varchar(5)
AS
SET NOCOUNT ON;
Select name, address, post
from tblPeople
where (name = @Name or @Name IS NULL) and
(address = @Address or @Address IS NULL) and
(post = @Post or @Post IS NULL)
一个简单的例子VB.NET调用存储过程:
Dim strName As String = NameTextBox.Value
Dim strAddress as string = AddressTextBox.Value
Dim strPost as string = PostTextBox.Value
Dim strSQL As String = "uspGetPeople"
Dim strConn As String = "My.Database.ConnectionString"
Dim cn As New SqlConnection(strConn)
Dim cmd As New SqlCommand(strSQL, cn)
cmd.CommandType = CommandType.StoredProcedure
If not string.isnullorempty(strName) then
cmd.Parameters.AddWithValue("@Name", strName)
Else
cmd.Parameters.AddWithValue("@Name", dbnull.value)
End if
If not string.isnullorempty(strPost) then
cmd.Parameters.AddWithValue("@Post", strPost)
Else
cmd.Parameters.AddWithValue("@Post", dbnull.value)
End if
If not string.isnullorempty(strAddress) then
cmd.Parameters.AddWithValue("@Address", strAddress)
Else
cmd.Parameters.AddWithValue("@Address", dbnull.value)
End if
Dim dr As SqlDataReader
Using cn
cn.Open()
dr = cmd.ExecuteReader
While dr.Read
'process records returned
'dr("name")
'dr("address")
'dr("post")
End While
cn.Close()
End Using