我想操作的是利用SqlDataAdapter的几个Command属性(InsertCommand,UpdateCommand,DeleteCommand)来更新数据库
代码:
SqlConnection conn = new SqlConnection(@"Data Source=.\sqlexpress;Initial Catalog=newsystem;Integrated Security=True");
SqlDataAdapter da = new SqlDataAdapter("select * from comment", conn);
//这里的构造函数直接实例化了SelectCommand所需要的SqlCommand了吧?
DataSet ds = new DataSet("myds");
da.FillSchema(ds, SchemaType.Source, "comment");
da.Fill(ds, "comment");
//接下来设置InsertCommand所需要的SqlCommand
SqlCommand incmd=new SqlCommand("insert into comment (****) values(****)",conn);
da.InsertCommand = incmd;
//接下来是更新到数据库
da.Update(ds.Tables["comment"]);
ds.Tables["comment"].AcceptChanges();
可到数据库里一看,悲剧发生了:没有插入该条记录!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
网上一查:有些说要实例化SqlCommandBuilder,可我觉得我的InsertCommand所需要的SqlCommand都写好了,不需要这样吧！
SqlCommandBuilder好像只是适用于直接修改DataSet,由SqlCommandBuilder自动生成所需的SQL语句:
SqlConnection conn = new SqlConnection(@"Data Source=.\sqlexpress;Initial Catalog=newsystem;Integrated Security=True");
SqlDataAdapter da = new SqlDataAdapter("select * from comment", conn);
SqlCommandBuilder cmdb = new SqlCommandBuilder(da);
DataSet ds = new DataSet("myds");
da.FillSchema(ds, SchemaType.Source, "comment");
da.Fill(ds, "comment");
ds.Tables["comment"].Rows[5]["content"] = "Can you help me???";
da.Update(ds.Tables["comment"]);
ds.Tables["comment"].AcceptChanges();
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public static SqlDataAdapter CreateCustomerAdapter( SqlConnection connection)
{
SqlDataAdapter adapter = new SqlDataAdapter(); // Create the SelectCommand.
SqlCommand command = new SqlCommand("SELECT * FROM Customers " +
"WHERE Country = @Country AND City = @City", connection); // Add the parameters for the SelectCommand.
command.Parameters.Add("@Country", SqlDbType.NVarChar, 15);
command.Parameters.Add("@City", SqlDbType.NVarChar, 15); adapter.SelectCommand = command; // Create the InsertCommand.
command = new SqlCommand(
"INSERT INTO Customers (CustomerID, CompanyName) " +
"VALUES (@CustomerID, @CompanyName)", connection); // Add the parameters for the InsertCommand.
command.Parameters.Add("@CustomerID", SqlDbType.NChar, 5, "CustomerID");
command.Parameters.Add("@CompanyName", SqlDbType.NVarChar, 40, "CompanyName"); adapter.InsertCommand = command; // Create the UpdateCommand.
command = new SqlCommand(
"UPDATE Customers SET CustomerID = @CustomerID, CompanyName = @CompanyName " +
"WHERE CustomerID = @oldCustomerID", connection); // Add the parameters for the UpdateCommand.
command.Parameters.Add("@CustomerID", SqlDbType.NChar, 5, "CustomerID");
command.Parameters.Add("@CompanyName", SqlDbType.NVarChar, 40, "CompanyName");
SqlParameter parameter = command.Parameters.Add(
"@oldCustomerID", SqlDbType.NChar, 5, "CustomerID");
parameter.SourceVersion = DataRowVersion.Original; adapter.UpdateCommand = command; // Create the DeleteCommand.
command = new SqlCommand(
"DELETE FROM Customers WHERE CustomerID = @CustomerID", connection); // Add the parameters for the DeleteCommand.
parameter = command.Parameters.Add(
"@CustomerID", SqlDbType.NChar, 5, "CustomerID");
parameter.SourceVersion = DataRowVersion.Original; adapter.DeleteCommand = command; return adapter;
}