predicate

问题 How can inner join be done on Many to Many relations using Predicate BooleanExpression? I have 2 entities public class A { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Integer id; @ManyToMany(fetch = FetchType.LAZY, cascade = { CascadeType.DETACH, CascadeType.MERGE, CascadeType.REFRESH, CascadeType.PERSIST}) @JoinTable(name = "a_b_maps", joinColumns = @JoinColumn(name = "a_id", nullable = false,referencedColumnName = "id"), inverseJoinColumns = @JoinColumn(name = "b_id",

问题 I need to compare DATE format from a DATETIME. Prior ZF 2.3.5, the following code was working fine: $select->where('DATE(arrival_date) <= DATE(NOW())'); $select->where('DATE(departure_date) >= DATE(NOW())'); $select->where('enable = true'); With ZF 2.4.2+ it does not work anymore and produce the following error: Cannot inherit previously-inherited or override constant TYPE_IDENTIFIER from interface Zend\Db\Sql\Predicate\PredicateInterface I have tried the following (without error). The

问题 This is my table The selected column is the one that I'm using in Predicate My first approach was public void betweenPredicate(String attrib, LocalDate value, LocalDate value2) { Predicate predicate = builder.between(entity.<LocalDate> get(attrib), builder.literal(value), builder.literal(value2)); predList.add(predicate); } But in that way some date are missing, so I change to this public void betweenPredicate(String attrib, LocalDate value, LocalDate value2) { Predicate predicate = builder

问题 I have a problem in Expression I have an Entity public class User{ public string Username{get;set;} public int PhoneNumber{get;set;} public string FIrstName{get;set;} public string LastName{get;set;} } and I have a DTO public class DTOUser{ public string Username{get;set;} public int PhoneNumber{get;set;} public string FIrstName{get;set;} public string LastName{get;set;} } Then I have a snippet code generic public IList<DTOUser> SelectAll(Expression<Func<DTOUser, bool>> predicate) { using

问题 I use this piece of code (found on stackoverflow) to generate a predicate static class BuilderPredicate { public static Expression<Func<T, bool>> True<T>() { return f => true; } public static Expression<Func<T, bool>> False<T>() { return f => false; } public static Expression<Func<T, bool>> Or<T>(this Expression<Func<T, bool>> expr1, Expression<Func<T, bool>> expr2) { var invokedExpr = Expression.Invoke(expr2, expr1.Parameters.Cast<Expression>()); return Expression.Lambda<Func<T, bool>>

问题 append/3 is a very powerful predicate. Suppose I want a predicate that works the same way but for SWI-Prolog's strings. The easiest approach I see is to transform those strings into lists with string_codes/2 , then apply append/3 , then use string_codes/2 back. The big problem with this approach is that string_codes/2 does not work if both variables are not unified. Here is an extremely ugly solution I came up with, which checks which strings are unified to apply string_codes/2 when needed:

问题 I have viewed numerous predicate questions, I have read the docs and nothing seems to be jumping out as an answer my problem. I have a Core Data entity named Materials and I have the Attributes category , subcategory and description . I have three UITableViewControllers and in each I want to use a predicate to display as follows: TableViewController 1: Only the categories (no repeating of category names) Select a category and go to TableViewController 2. TableViewController 2: Display

问题 I'm trying to write a function that determines if a number is divisible by 2 or 3. From what i've read online there is already a Scheme predicate divisible? but it is not working for me. I've tried writing one myself, but I don't know how to write a predicate function. Is there any help I can get? Thanks! 回答1: The divisible? predicate can be expressed in terms of the remainder procedure, remember: a number n is divisible by x if the remainder of dividing n by x is zero. (define (divisible? n

问题 I'm studying for an exam, and I'm not really sure how to portray this: The domain is all people. V (w) = w is a voter P (w) = w is a politician K (y, z) = y knows z T (y, z) = y trusts z Cal is a voter who knows everyone. (Cal is c) Would this be: ∀x V(c)^K(c,x) There is a politician that no other politician trusts ∃x∀y P(x)^P(y)^T(y,x) I'm not sure if those are right. Wouldn't the last one be saying: There are politicians that no one trusts? How do I make it singular? Also: No one trusts

问题 Unless I am missing something or missunderstand the mechanism (very likely) Shouldn't the "1" duplicate not exist in this vector ? chunks.erase( std::unique ( chunks.begin(), chunks.end(), []( std::string &s1, std::string &s2 ){ return ( s1.compare(s2) == 0 ? true : false );}), chunks.end() ); Before Executing the above: 1 l:1 1+ l:2 1+1 l:3 1+1= l:4 + l:1 +1 l:2 +1= l:3 1 l:1 1= l:2 = l:1 After executing the above code: 1 l:1 1+ l:2 1+1 l:3 1+1= l:4 + l:1 +1 l:2 +1= l:3 1 l:1 1= l:2 = l:1 I