Query with ternary operator in LINQ Where clause fails

[petriq]

Library name and version

• Kros.KORM 6.2.0

Description

When applying OData query options to IQueryable object, the OData self creates expressions for Where, OrderBy and other parts of a LINQ query. In some cases it produces Where expressions with ternary operator, which KORM fails to parse into SQL command.

Steps To Reproduce

var searchtext = "kro";
var test2 = _database.Query<MovementsOverviewSearchResult>()
    .Where(x => (x.PartnerName == null ? null : x.PartnerName.ToLower()) == null || 
        x.PartnerName.ToLower().Contains(searchtext))
    .OrderByDescending(x => x.MovementDate);

I know the Where condition in example is not 'optimal', but something like that OData produces for $filter=contains(tolower(PartnerName) 'kro') query string param.

Expected behavior

Parsed WHERE clause from example above should be like

WHERE ((CASE WHEN PartnerName IS NULL THEN NULL ELSE LOWER(PartnerName) END) IS NULL) OR (LOWER(PartnerName) LIKE '%' + @1 + '%')))

Also comparing something to NULL should be done by IS NULL, not = NULL. In TSQL comparing NULL = NULL produces FALSE. See separate issue #110 .

Actual behavior

The example provided above produces this SELECT statement:

SELECT ...  -- colums omitted   
FROM ...    -- table name omitted
WHERE ((((PartnerName = NULL)NULLLOWER(PartnerName) = NULL) OR (LOWER(PartnerName) LIKE '%' + @1 + '%'))) ORDER BY MovementDate DESC
  WITH PARAMETERS (kro)

Notice NULLLOWER in the WHERE clause. That is the place where ternary operator should be - well, or rather (CASE WHEN ... THEN ... ELSE ... END).

The query fails on SqlException: Incorrect syntax near 'NULLOWER'. Incorrect syntax near 'PartnerName'.