从Linq查询结果构建原始SQL字符串？

Question

I need to make a selection from a SQL Server table and concatenate the results into a SQL string so I end up with var sqlString = "Select blah from myTable where blah blah order by blah" :

Here's my LINQ. I'm trying to select out the columns in the order I need them & concatanate them into 1 string:

  var query = (from a in _Context.tbArticleTypeAssets
                      where a.ArticleType == ArticleType
                      select new {sqlQuery = a.ColSelection + "" + a.FromTable + "" + a.whereclause + "" + a.orderBY});

         string queryResult = query.ToString();

The result is a Linq output which I don't want. I just want the values of the strings. Is there a way to achieve this?

Answer 1

linq query will return a collection, you have to use First() or FirstOrDefault() to get the item :

 string queryResult = query.FirstOrDefault().sqlQuery;

better is to check for null as well:

string queryResult =  query.FirstOrDefault() != null ? query.FirstOrDefault().sqlQuery : string.Empty;

Answer 2

Try this:

 var query = _Context.tbArticleTypeAssets
        .Where(a=>a.ArticleType == ArticleType)
        .Select(a=>a.ColSelection + "" + a.FromTable + "" + a.whereclause + "" + a.orderBY)
        .ToList();

or if your query will always only return one record, then you can do this:

 var query = _Context.tbArticleTypeAssets
        .Where(a=>a.ArticleType == ArticleType)
        .Select(a=>a.ColSelection + "" + a.FromTable + "" + a.whereclause + "" + a.orderBY)
        .First();