already have started crud with blazor serverside to get data from database

i am working now to create a page where i will see details and edit one item of a list

i got the id of the item i want to display but my crud solution give me a list of object not just one llike i need....

i got my SqlDataAccess where i code the two main function (load -> QueryAsync, and Save -> ExecuteAsync) with its interface like below :

And i got a FiledbData class from where i call db like below :

i want now just to ask the database for one item like an getbyId instead of get all data ...

CodePudding user response：

You can use parameterized queries to execute an where clause.

Therefore the GetFile method would be like this:

public Task<FileModel> GetFilebyId(int id)
{
    string sql = "select * from dbo.file.. where Id = @Id";
    return _db.LoadSingleResult<FileModel, dynamic>(sql, new  {Id = id });
}

Also you need to add a new method LoadSingleResult like below(other parts apart from try section are similar to your LoadData method):

public async Task<T> LoadSingleResult<T,U>(string sql, U parameters)
{
   .
   .
   .
   try{
       var data=await connection.QueryAsynch<T>(sql, parameters);
       reurn data.Single();
   }
   .
   .
   .
}

Note that:

• The id column assumed to be Id.
• The id column assumed to be an integer column

You can use QuerySingleOrDefaultAsync too.

CodePudding user response：

Add a where clause to your DB SQL query and create an overload of GetFiles() that takes an ID value which will be interpolated into the SQL query:

public Task<List<FileModel>> GetFile(Guid id)
{
    string sql = $"select * from myTable where Id = '{id:D}'";

    return _db.LoadData<FileModel, dynamic>(sql, new  { });
}