使用1個表中的數據查詢另一個表

Question

我有2個表。我想使用名字表中的'First_Name'和'Middle_Name'來從DESCRIPTION表中獲取'Description'。我可以知道如何在SQL和LINQ表達式中構造這個查詢！非常感謝！

CREATE TABLE NAME (
    TICKET_ID int NOT NULL, 
    First_Name varchar(255), 
    Middle_Name varchar(255), 
    PRIMARY KEY (NAME) 
); 

INSERT INTO @NAME VALUES 
(1, 'alex', 'black'), 
(2, 'john', 'hudson'), 
(3, 'alice', 'channing') 


CREATE TABLE description(
    description_id int NOT NULL, 
    First_Name varchar(255), 
    Middle_Name varchar(255), 
    Description varchar(255), 
    PRIMARY KEY (description_id) 
); 

INSERT INTO @description 
(1, 'alex', 'black' , 'tall'), 
(2, 'john', 'hudson', 'strong'), 
(3, 'alice', 'channing', 'short') 

Answer 1

SQL：

select d.Description from #description d join #name n on d.First_name=n.first_name and d.last_name=n.last_name

的Linq：

from d in description join n in name on new on new { d.First_name, d.last_name } equals new { n.first_name, n.last_name } select new { d.Description}

Answer 2

CREATE TABLE #NAME (
    TICKET_ID int NOT NULL, 
    First_Name varchar(255), 
    Middle_Name varchar(255), 

); 

INSERT INTO #NAME VALUES 
(1, 'alex', 'black'), 
(2, 'john', 'hudson'), 
(3, 'alice', 'channing') 


CREATE TABLE #description(
    description_id int NOT NULL, 
    First_Name varchar(255), 
    Middle_Name varchar(255), 
    Description varchar(255), 
    PRIMARY KEY (description_id) 
); 

INSERT INTO #description values 
(1, 'alex', 'black' , 'tall'), 
(2, 'john', 'hudson', 'strong'), 
(3, 'alice', 'channing', 'short') 

select Description from #NAME A join 
#description B on b.First_Name=a.First_Name 
and b.Middle_Name=a.Middle_Name