我正在尝试使用CommandBuilder进行更新。当获取数据的代码被按钮命令获取时,代码完美工作,但是当我从page_load获取数据时,更新失败。sqlCommandBuilder更新不能按预期工作
该程序只是从数据库中提取数据,然后使用sqlCommandBuilder在特定的表上进行更新。
我不知道是怎么回事。
这是失败的代码。
private Users users;
protected void Page_Load(object sender, EventArgs e)
{
users = (Users)Session["Users"];
string connectionString = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;
SqlConnection connection = new SqlConnection(connectionString);
string selectQuery = "Select * from Candidate where Candidate_ID = " + users.Candidate_ID;
SqlDataAdapter dataAdapter = new SqlDataAdapter(selectQuery, connection);
DataSet dataSet = new DataSet();
dataAdapter.Fill(dataSet, "Candidates");
ViewState["DATASET"] = dataSet;
ViewState["SELECT_QUERY"] = selectQuery;
if (dataSet.Tables["Candidates"].Rows.Count > 0)
{
DataRow dataRow = dataSet.Tables["Candidates"].Rows[0];
txtLastName.Text = dataRow["LastName"].ToString();
txtCity.Text = dataRow["City"].ToString();
ddlGender.SelectedValue = dataRow["Gender"].ToString();
lblStatus.Text = "";
}
else
{
lblStatus.ForeColor = System.Drawing.Color.Red;
lblStatus.Text = "No record with ID = " + txtCandidateID.Text;
}
}
protected void btnUpdate_Click(object sender, EventArgs e)
{
string connectionString = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;
SqlConnection con = new SqlConnection(connectionString);
SqlDataAdapter dataAdapter = new SqlDataAdapter();
dataAdapter.SelectCommand = new SqlCommand((string)ViewState["SELECT_QUERY"], con);
SqlCommandBuilder builder = new SqlCommandBuilder(dataAdapter);
DataSet ds = (DataSet)ViewState["DATASET"];
DataRow dr = ds.Tables["Candidates"].Rows[0];
dr["LastName"] = txtLastName.Text;
dr["Gender"] = ddlGender.SelectedValue;
dr["City"] = txtCity.Text;
int rowsUpdated = dataAdapter.Update(ds, "Candidates");
if (rowsUpdated == 0)
{
lblStatus.ForeColor = System.Drawing.Color.Red;
lblStatus.Text = "No rows updated";
}
else
{
lblStatus.ForeColor = System.Drawing.Color.Green;
lblStatus.Text = rowsUpdated.ToString() + " row(s) updated";
}
}
这是完美的代码。
protected void Page_Load(object sender, EventArgs e)
{
}
protected void btnUpdate_Click(object sender, EventArgs e)
{
string connectionString = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;
SqlConnection con = new SqlConnection(connectionString);
SqlDataAdapter dataAdapter = new SqlDataAdapter();
dataAdapter.SelectCommand = new SqlCommand((string)ViewState["SELECT_QUERY"], con);
SqlCommandBuilder builder = new SqlCommandBuilder(dataAdapter);
DataSet ds = (DataSet)ViewState["DATASET"];
DataRow dr = ds.Tables["Candidates"].Rows[0];
dr["LastName"] = txtLastName.Text;
dr["Gender"] = ddlGender.SelectedValue;
dr["City"] = txtCity.Text;
int rowsUpdated = dataAdapter.Update(ds, "Candidates");
if (rowsUpdated == 0)
{
lblStatus.ForeColor = System.Drawing.Color.Red;
lblStatus.Text = "No rows updated";
}
else
{
lblStatus.ForeColor = System.Drawing.Color.Green;
lblStatus.Text = rowsUpdated.ToString() + " row(s) updated";
}
}
protected void btnFetchData_Click(object sender, EventArgs e)
{
users = (Users)Session["Users"];
string connectionString = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;
SqlConnection connection = new SqlConnection(connectionString);
string selectQuery = "Select * from Candidate where Candidate_ID = " + users.Candidate_ID;
SqlDataAdapter dataAdapter = new SqlDataAdapter(selectQuery, connection);
DataSet dataSet = new DataSet();
dataAdapter.Fill(dataSet, "Candidates");
ViewState["DATASET"] = dataSet;
ViewState["SELECT_QUERY"] = selectQuery;
if (dataSet.Tables["Candidates"].Rows.Count > 0)
{
DataRow dataRow = dataSet.Tables["Candidates"].Rows[0];
txtLastName.Text = dataRow["LastName"].ToString();
txtCity.Text = dataRow["City"].ToString();
ddlGender.SelectedValue = dataRow["Gender"].ToString();
lblStatus.Text = "";
}
else
{
lblStatus.ForeColor = System.Drawing.Color.Red;
lblStatus.Text = "No record with ID = " + txtCandidateID.Text;
}
}
什么不正确?你调试了你的代码吗?你得到任何异常或错误信息? Plesae更具体..你可以阅读[FAQ],[问]和[帮助]并请使用参数化查询。这种字符串连接对于SQL注入攻击是开放的。 –