使用 SqlCommandBuilder 时出现异常 "Incorrect syntax near 'System'"

Question

我正在学习 SqlCommandbuilder，但是当我尝试实现它时，出现异常。这是我的代码。

代码片段 #1：工作正常

protected void btnGetStudent_Click(object sender, EventArgs e)
{
    string cs = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;

    SqlConnection con = new SqlConnection(cs);
    SqlDataAdapter da = new SqlDataAdapter("Select * from tblStudents where ID = @Id", con);
    da.SelectCommand.Parameters.AddWithValue("@Id", txtStudentID.Text);

    DataSet ds = new DataSet();
    da.Fill(ds, "Students"); // now this FILL is very useful as it manages opening of the connection and then executing the command to get the data and the loading it into the dataset and then closes the connection.

    ViewState["SQL_Query"] = da.SelectCommand.ToString();
    ViewState["Data"] = ds;

    if (ds.Tables["Students"].Rows.Count > 0)
    {
        DataRow dr = ds.Tables["Students"].Rows[0];
        txtStudentID.Text = dr["Id"].ToString();
    }    
}

代码片段#2：导致异常：

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["SQL_Query"], con);
    SqlCommandBuilder builder = new SqlCommandBuilder(dataAdapter);

    DataSet ds = (DataSet)ViewState["Data"];
    DataRow dr = ds.Tables["Students"].Rows[0];
    dr["Id"] = txtStudentID.Text;

    int rowsUpdated = dataAdapter.Update(ds, "Students"); // Exception
}

异常：

Incorrect syntax near 'System'

Answer 1

我找到原因了：您关注的视频使用 .NET 2.0。我怎么知道？

查看 SqlCommandBuilder class 的文档：

.NET 2.0 示例：

DataSet dataSet = new DataSet();
adapter.Fill(dataSet, tableName);

//code to modify data in DataSet here

//Without the SqlCommandBuilder this line would fail
adapter.Update(dataSet, tableName);

.NET 3.0+ 示例：

DataSet dataSet = new DataSet();
adapter.Fill(dataSet, tableName);

//code to modify data in DataSet here

builder.GetUpdateCommand();

//Without the SqlCommandBuilder this line would fail
adapter.Update(dataSet, tableName);

它们之间的明显区别是在调用 adapter.Update 之前先调用 builder.GetUpdateCommand();，所以你错过了。

那是说：我建议您切换到一些至少使用 .NET 4.5

的教程

使用 SqlCommandBuilder 时出现异常 "Incorrect syntax near 'System'"

Getting Exception "Incorrect syntax near 'System'" while using SqlCommandBuilder

.net

c#

sql-server

ado.net