问题
I am using ASP.net Core 3.0 with Entity Framework Core 3.0 and Pomelo.EntityFrameworkCore provider for MySQL, I need to query all the users that are from specific Towns.
Lets say for example I have a list of strings called targettedTowns in which I have the following towns
var targettedTowns = new List<string>() {"korangi","landhi","zia colony","shah faisal","quaidabad"};
- korangi
- landhi
- zia colony
- shah faisal
- quaidabad
Now I want to find all the users that are located in the targettedTowns list using Linq Lambda syntax.
Users in my database have their towns saved like
- Korangi
- Korangi-Zia Colony
- Korangi-Bhittai Colony
- Korangi-Allah Wala Town
- Landhi-Sherpao
- Landhi-Awami Colony
- Landhi-Sherabad
- ShahFaisal
What I am trying currently is
var users = context.Users.Where(x => x.Town.ToLower().Contains(targettedList)).ToList();
but as String.Contains does not take a list in argument so I cant use this.
回答1:
You just need to replace x.Town.ToLower() with targettedList in where condition:
var users = context.Users.Where(x => targettedList.Contains(x.Town)).ToList();
来源：https://stackoverflow.com/questions/60914868/linq-to-entities-string-contains-a-list