PathConstraintNull (InterMine 5.0.0 API)

java.lang.Object
- org.intermine.pathquery.PathConstraint
- - org.intermine.pathquery.PathConstraintNull

```
public class PathConstraintNull
extends PathConstraint
```
Representation of a null attribute constraint in the PathQuery

Author:

Matthew Wakeling

- Field Summary
  
  Fields
  Modifier and Type Field Description
  
  static java.util.Set<ConstraintOp> VALID_OPS
  List of valid ops for this type of constraint
  - Fields inherited from class org.intermine.pathquery.PathConstraint
    op, path
- Constructor Summary
  
  Constructors
  Constructor Description
  
  PathConstraintNull(java.lang.String path, ConstraintOp op)
  Constructs a new PathConstraintNull.
- Method Summary
  
  All Methods Instance Methods Concrete Methods
  Modifier and Type Method Description
  
  java.lang.String toString()
  - Methods inherited from class org.intermine.pathquery.PathConstraint
    getExtraValue, getIds, getOp, getPath, getType, getValue, getValues
  - Methods inherited from class java.lang.Object
    clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - VALID_OPS
```
public static final java.util.Set<ConstraintOp> VALID_OPS
```
    List of valid ops for this type of constraint
- Constructor Detail
  - PathConstraintNull
```
public PathConstraintNull(java.lang.String path,
                          ConstraintOp op)
```
    Constructs a new PathConstraintNull. The path should be a normal path expression with dots separating the parts. Do not use colons to represent outer joins, and do not use square brackets to represent subclass constraints. The path will be checked for format, but can only be verified once inside a PathQuery object by the PathQuery.verifyQuery() method. This object is used to form an is_null or is_not_null constraint on an attribute.
    
    Parameters:
    
    path - the path that the constraint is attached to
    
    op - the type of operation
    
    Throws:
    
    java.lang.NullPointerException - if path or op are null
    
    java.lang.IllegalArgumentException - if the path contains colons or square brackets, or is otherwise in a bad format, or if the op is invalid for this constraint type
- Method Detail
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object