Question

CREATE TABLE [MyNames]
(
    [ID] INT IDENTITY PRIMARY KEY,
    [Name] NVARCHAR(255) NULL
)

INSERT INTO [MyNames] VALUES ('John')
INSERT INTO [MyNames] VALUES ('Jane')
INSERT INTO [MyNames] VALUES ('Peter')
INSERT INTO [MyNames] VALUES ('Montgomery')
INSERT INTO [MyNames] VALUES ('Sarah')

基于上述（假设的）SQL架构和数据，我想使用Linq to SQL获取名称> 数组值的所有结果。

string[] names = {"John", "Cassandra", "Sarah"};

var results = (from n in db.Names
               where n.Name **in names**
               select n).ToList();

结果应包括John和Sarah。有了这些信息，我就可以添加需要添加的条目，在本例中为Cassandra。

我不想加载所有名称，因为列表可能会异常长。

Answer 1

您可以使用names.Contains()：

string[] names = {"John", "Cassandra", "Sarah"};

var results = (from n in db.Names
               where names.Contains(n.Name)
               select n).ToList();

Answer 2

您可以使用Contains扩展名方法：

var results = (from n in db.Names
               where names.Contains(n.Name)
               select n).ToList();

Answer 3

var results = (from n in db.Names
               where names.Any(x=>x == n.Name)
               select n).ToList();

Linq to SQL：WHERE IN语句

3 个答案: