如何在頁面加載時顯示從表到網格視圖的記錄，以及如何使用文本框vb.net搜索特定字段的記錄？

Question

我的數據庫：table1

ID             FIRSTNAME              AGE
1              Sumit                  22
2              Sanjeev                23

我有gridview 1和textbox1和button1

我想當頁面加載時，gridview顯示表1中的所有記錄，並且... ii要通過在textbox1中鍵入sumit並單擊button1來搜索名字的記錄，然后在gridview中將顯示..的記錄默認情況下gridview display alll表1中的記錄

這個怎么做 ？

我的Selct查詢如下：但它不顯示所有記錄...但是如果您搜索特定記錄，它可以顯示記錄...

SELECT a1_admins.EmployeeId, a1_admins.Firstname, a1_admins.Lastname, a1_admins.Email
, a1_admins.City, a1_admins.State, a1_admins.Country, aspnet_Membership.LastLoginDate
, aspnet_Membership.CreateDate, a1_admins.Password, a1_admins.pan_no, a1_admins.Contactno
, a1_admins.Address 
FROM a1_admins 
INNER JOIN aspnet_Membership 
ON a1_admins.UserId = aspnet_Membership.UserId 
WHERE (a1_admins.EmployeeId LIKE N'%' + @EmployeeId + N'%') 
    OR (a1_admins.City LIKE N'%' + @City + N'%') 
    OR (a1_admins.State LIKE N'%' + @State + N'%') 
    OR (a1_admins.Country LIKE N'%' + @Country + N'%')

Answer 1

我假設未過濾時將變量設置為NULL？ 這將導致X LIKE NULL失敗，因為X LIKE NULL不能為true。

SELECT
  a1_admins.EmployeeId, a1_admins.Firstname, a1_admins.Lastname, a1_admins.Email, 
  a1_admins.City, a1_admins.State, a1_admins.Country, aspnet_Membership.LastLoginDate, 
  aspnet_Membership.CreateDate, a1_admins.Password, a1_admins.pan_no, a1_admins.Contactno, a1_admins.Address 
FROM a1_admins 
INNER JOIN aspnet_Membership ON a1_admins.UserId = aspnet_Membership.UserId 
WHERE (a1_admins.EmployeeId LIKE N'%' + @EmployeeId + N'%') 
   OR (a1_admins.City LIKE N'%' + @City + N'%') 
   OR (a1_admins.State LIKE N'%' + @State + N'%') 
   OR (a1_admins.Country LIKE N'%' + @Country + N'%')
   OR (Coalesce(@employeeid,@city,@state,@country) is null)

您可以添加last子句，如果未設置所有過濾器，則顯示所有內容。