关于SqlDataAdapter的几个Command属性的疑问
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[已解决问题]
解决于 2011-02-01 20:40
http://topic.csdn.net/u/20071119/17/9316fdc5-5993-4720-a8e7-0d4ab5e28528.html
上面的问题就是我碰到的
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();
最佳答案
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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; }
public static DataSet GetCustomerData(string dataSetName,
string connectionString)
{
DataSet dataSet = new DataSet(dataSetName);
using (SqlConnection connection = new SqlConnection(connectionString))
{
SqlDataAdapter adapter = new SqlDataAdapter(
"SELECT CustomerID, CompanyName, ContactName FROM dbo.Customers", connection);
DataTableMapping mapping = adapter.TableMappings.Add("Table", "Customers");
mapping.ColumnMappings.Add("CompanyName", "Name");
mapping.ColumnMappings.Add("ContactName", "Contact");
connection.Open();
adapter.FillSchema(dataSet, SchemaType.Mapped);
adapter.Fill(dataSet);
return dataSet;
}
}
看官方资料 很多
