Multiple joins and logical operators

Question

I would need some guidance to convert this query in LINQ (method-based or expression syntax):

SELECT * from table1 t1 
JOIN table2 t2 ON t1.fieldA = t2.fieldA and t1.fieldB = t2.fieldB 
JOIN table3 t3 ON t2.fieldC = t3.fieldA
WHERE 
    t3.Enabled=1 and 
    t2.Active = 1 and
    t1.Linked=1;

Using expression syntax it seems logical operators are not supported in the join clause.

My failed attempt:

var query = from t1 in context.table1
            join t2 in context.table2 on t1.fieldA equals t2.fieldB && t1.fieldB equals t2.fieldB
            join t3 in context.table3 on t3.fieldA equals t3.fieldC
            where 
                t1.Enabled == 1 && t2.Active == 1 && t3.Linked == 1;

Possible duplicate of [LINQ to SQL: Multiple joins ON multiple Columns. Is this possible?](https://stackoverflow.com/questions/5307731/linq-to-sql-multiple-joins-on-multiple-columns-is-this-possible) — JustLearning, Jun 22 '18 at 08:34
check this out : https://stackoverflow.com/questions/5307731/linq-to-sql-multiple-joins-on-multiple-columns-is-this-possible — JustLearning, Jun 22 '18 at 08:34

score 1 · Accepted Answer · answered Jun 22 '18 at 08:39

EF does not support multiple objects to be used for joining, instead, you can create object that will contain all properties you want to apply equals on:

var query = from t1 in context.table1
            join t2 in context.table2 on new {t1.fieldA, t1.fieldB} equals new {t2.fieldA, t2.fieldB}
            join t3 in context.table3 on t3.fieldA equals t3.fieldC
            where 
                t1.Enabled == 1 && t2.Active == 1 && t3.Linked == 1 ...

score 0 · Answer 2 · answered Jun 22 '18 at 08:47

0

you code has wrong third condition instead of

join t3 in context.table3 on t3.fieldA equals t3.fieldC

put

join t3 in context.table3 on t2.fieldC equals t3.fieldA

answered Jun 22 '18 at 08:47

godpanrupesh

45
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Multiple joins and logical operators

2 Answers2