更新时间:2021-12-11 00:08:19
是的,您可以在顶部使用Entity Framework 4和LINQ,它会生成参数化查询并执行它,这是选项.
Yes, you can use Entity Framework 4 and LINQ on top, it generates the parametrized query and executes it, that's the option.
另一个选择是(并且我做了几次)来创建基类/接口,比如:
Another option is (and I did several times) to create a base class/interface, let's say:
public interface IExecutable
{
void Execute(IConnection connection);
}
public interface IExecutable<TResult> : IExecutable
{
TResult Result { get; }
}
public abstract ActionBase<TResult> : IExecutable<TResult>
{
protected void AddParameter(....);
protected IDataReader ExecuteAsReader(string query) {
//create a DB Command, open transaction if needed, execute query, return a reader.
}
protected object ExecuteAsScalar(string query) {
//....
}
//the concrete implementation
protected abstract TResult ExecuteInternal();
IExecutable.Execute(IConnection connection) {
//keep the connection
this.Result = ExecuteInternal();
}
//another common logic:
}
然后您可以创建自己的具体操作:
Then you can create your concrete actions:
public sealed class GetUsersAction : ActionBase<<IList<User>>
{
//just a constructor, you provide it with all the information it neads
//to be able to generate a correct SQL for this specific situation
public GetUsersAction(int departmentId) {
AddParameter("@depId", departmentId);
}
protected override IList<User> ExecuteInternal() {
var command = GenerateYourSqlCommand();
using(var reader = ExecuteAsReader(command)) {
while(reader.Read) {
//create your users from reader
}
}
//return users you have created
}
}
非常容易创建具体动作!
Very easy to create concrete actions!
然后,为了使其变得更加简单,创建一个ExecutionManager,其关注点是如何获得连接并执行操作:
Then, to make it even easier, create an ExecutionManager whose concern is how to get the connection and execute the action:
public sealed ExecutionManager() {
TResult Execute<TResult>(IExecutable<TResult> action) {
var connection = OhOnlyIKnowHowTOGetTheConnectionAnfHereItIs();
action.Execute(connection);
return action.Result;
}
}
现在就使用它:
var getUsersAction = new GetUsersAction(salesDepartmentId);
//it is not necessary to be a singletone, up to you
var users = ExecutionManager.Instance.Execute(getUsersAction);
//OR, if you think it is not up to ExecutionManager to know about the results:
ExecutionManager.Instance.Execute(getUsersAction);
var users = getUsersAction.Result
使用这种简单的技术,将所有连接/命令/执行逻辑从具体动作移到基类中确实很容易,而具体动作所关心的只是生成SQL,并将数据库输出转换为有意义的结果.
Using this simple technique it is really easy to move all the connection/command/execution logic away from the concrete actions into the base class, and the concrete actions' concerns are just generating SQLs and converting database output into some meaningful results.
祝你好运:)