Package org.apache.sis.storage

Class FeatureQuery.NamedExpression

java.lang.Object
org.apache.sis.storage.FeatureQuery.NamedExpression
All Implemented Interfaces:
Serializable
Enclosing class:
FeatureQuery
public static class FeatureQuery.NamedExpression extends Object implements Serializable
An expression to be retrieved by a Query, together with the name to assign to it. In relational database terminology, subset of columns is called projection. Columns can be given to the FeatureQuery.setProjection(NamedExpression[]) method.
Since:
1.1
Version:
1.2
See Also:

  • Field Details

    • serialVersionUID

      private static final long serialVersionUID
      For cross-version compatibility.
      See Also:

    • expression

      public final Expression<? super AbstractFeature,?> expression
      The literal, value reference or more complex expression to be retrieved by a Query. Never null.

    • alias

      public final org.opengis.util.GenericName alias
      The name to assign to the expression result, or null if unspecified.

  • Constructor Details

    • NamedExpression

      public NamedExpression(Expression<? super AbstractFeature,?> expression)
      Creates a new column with the given expression and no name.
      Parameters:
      expression - the literal, value reference or expression to be retrieved by a Query.

    • NamedExpression

      public NamedExpression(Expression<? super AbstractFeature,?> expression, org.opengis.util.GenericName alias)
      Creates a new column with the given expression and the given name.
      Parameters:
      expression - the literal, value reference or expression to be retrieved by a Query.
      alias - the name to assign to the expression result, or null if unspecified.

    • NamedExpression

      public NamedExpression(Expression<? super AbstractFeature,?> expression, String alias)
      Creates a new column with the given expression and the given name. This constructor creates a LocalName from the given string.
      Parameters:
      expression - the literal, value reference or expression to be retrieved by a Query.
      alias - the name to assign to the expression result, or null if unspecified.

  • Method Details

    • hashCode

      public int hashCode()
      Returns a hash code value for this column.
      Overrides:
      hashCode in class Object
      Returns:
      a hash code value.

    • equals

      public boolean equals(Object obj)
      Compares this column with the given object for equality.
      Overrides:
      equals in class Object
      Parameters:
      obj - the object to compare with this column.
      Returns:
      whether the two objects are equal.

    • toString

      public String toString()
      Returns a string representation of this column for debugging purpose.
      Overrides:
      toString in class Object
      Returns:
      a string representation of this column.

    • appendTo

      final void appendTo(StringBuilder buffer)
      Appends a string representation of this column in the given buffer.