如何从组合框中获取值以插入到Sql [英] How Can I Get Value From Combo Box To Insert To Sql

问题描述

 SqlCommand cmd2 =  new  SqlCommand（  insertProducts_TBL，con2）; 
 cmd2.CommandType = System.Data.CommandType.StoredProcedure; 
 cmd2.Parameters.AddWithValue（  @ Product_name，txtProduct_name.Text）; 
 cmd2.Parameters.AddWithValue（  @ FK_catId，comboBoxFK_catid.SelectedValue）; 

解决方案

HI，我认为你的字段'FK_catId'是为什么会出现错误的int，所以你必须输入cast的combobox的字符串值如下所示整数，

 Convert.Toint32（comboBoxFK_catid.SelectedValue）

完整代码如下：

 SqlCommand cmd2 = new SqlCommand（insertProducts_TBL，con2）; 
 cmd2.CommandType = System.Data.CommandType.StoredProcedure; 
 cmd2.Parameters.AddWithValue（@ Product_name，txtProduct_name.Text）; 
 cmd2.Parameters.AddWithValue（@ FK_catId，Convert.Toint32（comboBoxFK_catid.SelectedValue））; 

使用

 SelectedItem 

而不是

 selectedValue 

您的错误消息表明 comboBoxFK_catid.SelectedValue 包含 DataRowView 。您必须知道要在数据库中插入该行的哪一列 - 我在此处用columnName指示它，将其替换为实际的列名：

 cmd2.Parameters.AddWithValue（
   @ FK_catId，
（（DataRowView ）comboBoxFK_catid.SelectedValue）[  columnName]）; 

SqlCommand cmd2 = new SqlCommand("insertProducts_TBL", con2);
                        cmd2.CommandType = System.Data.CommandType.StoredProcedure;
                        cmd2.Parameters.AddWithValue("@Product_name", txtProduct_name.Text);
                        cmd2.Parameters.AddWithValue("@FK_catId", comboBoxFK_catid.SelectedValue);

解决方案

HI, I think your field 'FK_catId' is int that why error could arise ,so you have to type cast the string value of combobox into integer like this below,

Convert.Toint32(comboBoxFK_catid.SelectedValue)

Full code below:

SqlCommand cmd2 = new SqlCommand("insertProducts_TBL", con2);
                        cmd2.CommandType = System.Data.CommandType.StoredProcedure;
                        cmd2.Parameters.AddWithValue("@Product_name", txtProduct_name.Text);
                        cmd2.Parameters.AddWithValue("@FK_catId", Convert.Toint32(comboBoxFK_catid.SelectedValue));

use

SelectedItem

instead of

selectedValue

Your error message indicates that comboBoxFK_catid.SelectedValue contains a DataRowView. You have to know which column of that row you want to insert into your database - I indicate it here with "columnName", replace that with the actual column name:

cmd2.Parameters.AddWithValue(
    "@FK_catId",
    ((DataRowView)comboBoxFK_catid.SelectedValue)["columnName"]);

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