如何将参数传递给SqlDataAdapter

本文介绍了如何将参数传递给SqlDataAdapter的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我有一个 Vb 程序，它查询数据库以获取一堆记录.我不太清楚如何传递参数.下面是我的代码:

I have a Vb program that queries a database to get a bunch of records. I can't quite figure out how to pass parameters. below is my code:

Dim connectionString As String Dim sqlCnn As SqlConnection Dim sqlCmd As SqlCommand Dim sql As String Private Function GetCustomerData() As DataTable locationdb = "10.0.1.1" connectionString = ("Data Source=" & locationdb & ";Initial Catalog=TestDB;Persist Security Info=True;User ID=user;Password=password") sql = ("SELECT lCustomerID,CustomerName,address FROM customers where @active = True...ETC") sqlCnn = New SqlConnection(connectionString) Dim CategoryAdapter As New SqlDataAdapter(sql, sqlCnn) Dim CustomerInfo As New DataSet() sqlCmd.Parameters.AddWithValue("@StartDate", frmMain.Startdate) sqlCmd.Parameters.AddWithValue("@EndDate", frmMain.Enddate) sqlCmd.Parameters.AddWithValue("@Department", "ALL") sqlCmd.Parameters.AddWithValue("@Active", "1") sqlCmd.Parameters.AddWithValue("@Visits", "ALL") CategoryAdapter.Fill(CustomerInfo, "Customers") Return CustomerInfo.Tables(0) End Function

我需要通过:

@stardate @enddate @Deparment @Active @Visits

我收到错误:

NullReferenceException was unhandled. Object reference not set to an instance of an object.

在线:

sqlCmd.Parameters.AddWithValue("@StartDate", frmMain.Startdate)

frmMain.Startdate 和 frmMain.Enddate 由 datetimepicker1 and datetimepicker2 上的日期时间选择器定义>frmMain

frmMain.Startdate and frmMain.Enddate are defined by a Datetime picker datetimepicker1 and datetimepicker2 on frmMain

推荐答案

这里有一个示例，说明您可以使用什么以及如何传递参数您必须在必要时进行更改

here is an example of what you can use and how to pass Parameters you have to make the changes where necessary

Public Shared Function GetCustomerInfo(stardate As DateTime, enddate As DateTime, Department As String, Active as String, Visits as Int33) As List(Of String) Dim cszList = New List(Of String)() Dim DSCityStateZipLookup As New DataSet() 'load the List one time to be used thru out the intire application Dim ConnString = System.Configuration.ConfigurationManager.ConnectionStrings("CMSConnectionString").ConnectionString Using connStr As New SqlConnection(ConnString) Using cmd As New SqlCommand("your Stored Proc name goes here", connStr) cmd.Parameters.AddWithValue("@stardate", stardate)//make sure you assign a value to startdate cmd.Parameters.AddWithValue("@enddate", enddate)//make sure you assign a value to enddate cmd.Parameters.AddWithValue("@Deparment", Deparment)//make sure you assign a value to //Department cmd.Parameters.AddWithValue("@Active", Active)//make sure you assign a value to Active cmd.Parameters.AddWithValue("@Visits", Visits)//make sure you assign a value to Visits cmd.Connection.Open() New SqlDataAdapter(cmd).Fill(DSCityStateZipLookup) 'If we get a record back from the above stored procedure call, that in itself means the information the user provided from 'the UI is in the database. On the other hand, if we do not get a record back from the stored procedure call, we should 'simply advise the user that the information they provided does not exist in the database, and to double check their spelling. If DSCityStateZipLookup.Tables.Count = 0 OrElse (DSCityStateZipLookup.Tables.Count > 0 AndAlso DSCityStateZipLookup.Tables(0).Rows.Count = 0) Then cszList.Add("Your Error Message goes here if any.") End If End Using End Using Return cszList End Function