[VB.NET]老问题，插入数据并发错误?
发布时间：2020-12-16 23:49:34 所属栏目：大数据 来源：网络整理
导读：老问题，插入数据并发错误? ''简单的数据存取.动态表.有主键，原因在于未能自动提升主键值。(用自动生成的数据集就没此问题) Imports System.Data.SqlClient Public Class Form1 Dim comm As New SqlClient.SqlConnection Dim ad As New SqlDataAdapter("SELE
|
老问题，插入数据并发错误? ''简单的数据存取.动态表.有主键，原因在于未能自动提升主键值。(用自动生成的数据集就没此问题) Imports System.Data.SqlClient Public Class Form1 Dim comm As New SqlClient.SqlConnection Dim ad As New SqlDataAdapter("SELECT * FROM 数据表",comm) Private Sub Form1_Load(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles MyBase.Load Dim st As String = "D:/temp/sql.mdf" Dim SqTex As String = "Data Source=./SQLEXPRESS;AttachDbFilename=" & st & ";Integrated Security=True;Connect Timeout=30;User Instance=True" comm.ConnectionString = SqTex comm.Open() Dim dber As New SqlCommandBuilder(ad) ad.DeleteCommand = dber.GetDeleteCommand ad.InsertCommand = dber.GetInsertCommand ad.UpdateCommand = dber.GetUpdateCommand Dim ds As New DataSet ad.FillSchema(ds,SchemaType.Mapped,"数据表") ad.Fill(ds,"数据表") DataGridView1.DataSource = ds DataGridView1.DataMember = "数据表" End Sub Private Sub DataGridView1_CellEndEdit(ByVal sender As Object,ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.CellEndEdit Try Me.Validate() Catch End Try Dim ds As DataSet =Ctype(DataGridView1.DataSource,DataSet) ad.Update(ds,"数据表") End Sub End Class __________________________________________________________________________ 什么问题? __________________________________________________________________________ 用解除约束试一试。 __________________________________________________________________________ 引用 1 楼 qinhl99 的回复: 什么问题? 1.)创建一个测试表 如: (先写入一条或多条记录) AAA BBB HHH 序号 ''----序号设为主键 .. .. .. 0 贴上代码执行，插入一条记录看会发生什么? __________________________________________________________________________ 今天忠于将问题解决了。还是老方法。 Dim cn As New SqlCommand("SELECT MAX(序号) FROM 数据表",comm) Dim sd As Integer = cn.ExecuteScalar + 1 ds.Tables("数据表").Columns("序号").AutoIncrement = True ds.Tables("数据表").Columns("序号").AutoIncrementSeed = sd ds.Tables("数据表").Columns("序号").AutoIncrementStep = 1 ''---------------------------- 用SQL语句设置的主键在更新的时候都要刷新填充表，表会滚动， 不知还有更好的方法? __________________________________________________________________________ 来学习了. __________________________________________________________________________ （编辑：李大同） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |