LinqToSql查詢，而不是一些SQL查詢

Question

SELECT * FROM register WHERE user_id LIKE 'a%' 

SELECT * FROM register WHERE user_id LIKE '%m' 

SELECT * FROM register WHERE user_id LIKE '%andru%' 


SELECT R.name,C.country_name,S.state_name 
FROM register R JOIN country C ON R.country_id=C.country_id 
JOIN state S ON R.state_id=S.state_id 

SELECT R.name,C.country_name,S.state_name 
FROM register R INNER JOIN country C ON R.country_id=C.country_id  
INNER JOIN state S ON R.state_id=S.state_id 

現在我需要LinqToSql查詢，而不是這些查詢

Answer 1

var result = context.Registers.Select(x => x.StartsWith(foo)).ToList(); 

result = context.Registers.Select(x => x.EndsWith(foo)).ToList(); 

result = context.Registers.Select(x => x.Contains(foo)).ToList(); 

result = from register in context.Registers 
     join state in context.States on register.state_id equals state.state_id 
     select new { register.name, state.country_name, state.state_name } 

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注意，inner join和join功能在SQL一樣的 - 因此沒有必要複雜化。