Question

我知道这是DataGridView的基本功能，但由于某种原因，我无法让它工作。我只希望Windows窗体上的DataGridView在用户单击“保存”按钮时向数据库提交对其进行的任何更改。

我根据DropDownList中用户选择触发的函数填充DataGridView，如下所示：

using (SqlConnection con = new SqlConnection(conString))
{
    con.Open();
    SqlDataAdapter ruleTableDA = new SqlDataAdapter("SELECT rule.fldFluteType AS [Flute], rule.fldKnife AS [Knife], rule.fldScore AS [Score], rule.fldLowKnife AS [Low Knife], rule.fldMatrixScore AS [Matrix Score], rule.fldMatrix AS [Matrix] FROM   dbo.tblRuleTypes rule WHERE rule.fldMachine_ID = '1003'", con);
    DataSet ruleTableDS = new DataSet();
    ruleTableDA.Fill(ruleTableDS);
    RuleTable.DataSource = ruleTableDS.Tables[0];
}

在我的保存功能中，我基本上有以下内容（我已经修剪了一些代码以便达到目的）：

using (SqlDataAdapter ruleTableDA = new SqlDataAdapter("SELECT rule.fldFluteType AS [Flute], rule.fldKnife AS [Knife], 
       rule.fldScore AS [Score], rule.fldLowKnife AS [Low Knife],
       rule.fldMatrixScore AS [Matrix Score], rule.fldMatrix AS [Matrix]
       FROM dbo.tblRuleTypes rule WHERE rule.fldMachine_ID = '1003'", con))
    {
        SqlCommandBuilder commandBuilder = new SqlCommandBuilder(ruleTableDA);
        DataTable dt = new DataTable();
        dt = RuleTable.DataSource as DataTable;
        ruleTableDA.Fill(dt);
        ruleTableDA.Update(dt);
    }

好的，所以我编辑了代码来执行以下操作：构建命令，基于DataGridView（RuleTable）创建DataTable，使用DataTable填充DataAdapter，并更新数据库。现在ruleTableDA.Update（dt）抛出异常“并发冲突：UpdateCommand影响了预期的1条记录中的0条。”

Answer 1

我相信这里有一些问题：要记住的顺序是，当您加载网格时，它已经指向数据表/集合。键入网格时，更改会暂时保留到绑定到网格的数据表中。因此，您不希望每次保存时都创建数据表，因为忽略了对现有数据表所做的更改。第二个问题是你可能不需要每次都创建一个绑定源，因为就像第一点一样，如果网格显示数据，那么它已经绑定了绑定源。第三个问题是SQLCommandBuilder类具有GetInsertCommand，GetUpdateCommand等方法，必须使用它们来实际获取相应的命令。

using (SqlDataAdapter ruleTableDA = new SqlDataAdapter("SELECT rule.fldFluteType AS [Flute], rule.fldKnife AS [Knife], 
       rule.fldScore AS [Score], rule.fldLowKnife AS [Low Knife],
       rule.fldMatrixScore AS [Matrix Score], rule.fldMatrix AS [Matrix]
       FROM dbo.tblRuleTypes rule WHERE rule.fldMachine_ID = '1003'", con))
    {
        SqlCommandBuilder commandBuilder = new SqlCommandBuilder(ruleTableDA);
        DataTable dt = new DataTable();
        dt = RuleTable.DataSource as DataTable;
        //ruleTableDA.Fill(dt);
        ruleTableDA.Update(dt);
    }

Answer 2

MSDN文档指出在手动设置SelectCommand时会自动设置update / delete / insert命令。它没有提到当你使用SqlDataAdapter构造一个时它也会这样做。尝试在创建SqlCommanduBuilder后添加这些行。

ruleTableDA.UpdateCommand = commandBuilder.GetUpdateCommand()
ruleTableDA.InsertCommand = commandBuilder.GetInsertCommand()
ruleTableDA.DeleteCommand = commandBuilder.GetDeleteCommand()

Answer 3

您可能需要这样才能获得更新命令

ruleTableDA.UpdateCommand = commandBuilder.GetUpdateCommand();

WinForms DataGridView - 更新数据库

3 个答案: