在SQL查询或LINQ中将多个联接表选择成多个变量

Question

SELECT O.*, U.*, C.*, P.*, S.* 
INTO OV, Usuarios, Clientes, Proposta, Status 
FROM[dbo].[TB_OV] O 
INNER JOIN dbo.TB_Usuarios U on U.id = O.userinsert 
INNER JOIN dbo.TB_Clientes C on C.id = O.ENDFAT 
INNER JOIN dbo.TB_Status S on S.id = O.status 
LEFT JOIN TB_Proposta P on P.id = O.ID_PROP 
WHERE O.status = 214 ORDER BY O.DTSOL, O.DtdeFaturamento

I am developing a web system in C# and one of the queries that I am trying to do is this one...
I want to know what is the correct syntax to do that or something like this.

What I need to know exactly is how to select this five tables into five different variables like an object to each one that I can cast later in C# to turn into object typed.

Otherwise, I've tried to do it with LINQ to SQL from C# and I still did not get any results from queries in LINQ to SQL to these tables.

Lambda:

var query = db.TB_OV
    .Join(db.TB_Usuarios, OV => OV.USERINSERT, U => U.ID, (OV, U) => new { OV, U })
    .Join(db.TB_Clientes, Z => Z.OV.ENDFAT, CL => CL.ID, (Z, CL) => new { Z, CL })
    .Join(db.TB_Status, Z => Z.Z.OV.STATUS, ST => ST.ID, (Z, ST) => new { Z, ST })
    .Join(db.TB_Proposta, Z => Z.Z.Z.OV.ID_PROP, P => P.ID, (Z, P) => new { Z, P })
    .Where(Z => Z.Z.Z.Z.OV.STATUS == 214)
    .Select(Z => new OperacoesListaSolFaturamento
    {
        OV = Z.Z.Z.Z.OV,
        Usuarios = Z.Z.Z.Z.U,
        Clientes = Z.Z.Z.CL,
        Status = Z.Z.ST,
        Proposta = Z.P
    });

Fluent:

var query = from O in db.TB_OV
            join U in db.TB_Usuarios on O.USERINSERT equals U.ID
            join C in db.TB_Clientes on O.ENDFAT equals C.ID
            join S in db.TB_Status on O.STATUS equals S.ID
            join P in db.TB_Proposta on O.ID_PROP equals P.ID
            where O.STATUS == 214
            select new OperacoesListaSolFaturamento
            {
                OV = O,
                Usuarios = U,
                Clientes = C,
                Status = S,
                Proposta = P
            };

Is there any way to do that? Either by LINQ or SQL queries.

Answer 1

For translating SQL to LINQ query comprehension:

1. Translate FROM subselects as separately declared variables.
2. Translate each clause in LINQ clause order, translating monadic and aggregate operators ( DISTINCT , TOP , MIN , MAX etc) into functions applied to the whole LINQ query.
3. Use table aliases as range variables. Use column aliases as anonymous type field names.
4. Use anonymous types ( new { ... } ) for multiple columns.
5. LEFT JOIN is simulated by using into joinvariable and doing another from from the joinvariable followed by .DefaultIfEmpty() .
6. Replace COALESCE with the conditional operator ( ?: )and a null test.
7. Translate IN to .Contains() and NOT IN to ! ... Contains() .
8. Translate x BETWEEN low AND high to low <= x && x <= high .
9. SELECT * must be replaced with select range_variable or for joins, an anonymous object containing all the range variables.
10. SELECT fields must be replaced with select new { ... } creating an anonymous object with all the desired fields or expressions.
11. Proper FULL OUTER JOIN must be handled with an extension method.

So the main problem with your fluent query is you didn't translate the LEFT JOIN properly:

var query = from O in db.TB_OV
            where O.STATUS == 214
            join U in db.TB_Usuarios on O.USERINSERT equals U.ID
            join C in db.TB_Clientes on O.ENDFAT equals C.ID
            join S in db.TB_Status on O.STATUS equals S.ID
            join P in db.TB_Proposta on O.ID_PROP equals P.ID into Pj
            from P in Pj.DefaultIfEmpty()
            orderby O.DTSOL, O.DtdeFaturamento
            select new OperacoesListaSolFaturamento
            {
                OV = O,
                Usuarios = U,
                Clientes = C,
                Status = S,
                Proposta = P
            };