Package adql.query.constraint

Class IsNull

java.lang.Object
adql.query.constraint.IsNull
All Implemented Interfaces:
ADQLObject, ADQLConstraint
public class IsNull extends Object implements ADQLConstraint
Represents a comparison between a column to the NULL value.

  • Field Details

    • FEATURE

      public static final LanguageFeature FEATURE
      Description of this ADQL Feature.
      Since:
      2.0

  • Constructor Details

    • IsNull

      public IsNull(ADQLColumn column) throws NullPointerException
      Builds a comparison between the given column and NULL.
      Parameters:
      column - The column whose the value must be compared to NULL.
      Throws:
      NullPointerException - If the given column is NULL.

    • IsNull

      public IsNull(ADQLColumn column, boolean isNot) throws NullPointerException
      Builds a comparison between the column and NULL.
      Parameters:
      column - The column whose the value must be compared to NULL.
      isNot - true means IS NOT NULL, false means IS NULL.
      Throws:
      NullPointerException - If the given column is NULL.

    • IsNull

      public IsNull(IsNull toCopy) throws Exception
      Builds a IsNull constraint by copying the given one.
      Parameters:
      toCopy - The IsNull to copy.
      Throws:
      Exception - If there is an error during the copy.

  • Method Details

    • getFeatureDescription

      public final LanguageFeature getFeatureDescription()
      Description copied from interface: ADQLObject
      Get the description of this ADQL's Language Feature.

      Note: Getting this description is generally only useful when discovery optional features so that determining if they are allowed to be used in ADQL queries.

      Specified by:
      getFeatureDescription in interface ADQLObject
      Returns:
      Description of this ADQL object as an ADQL's feature.

    • getColumn

      public final ADQLColumn getColumn()
      Gets the column whose the value is compared to NULL.
      Returns:
      The column compared to NULL.

    • setColumn

      public final void setColumn(ADQLColumn column) throws NullPointerException
      Lets changing the column whose the value must be compared to NULL.
      Parameters:
      column - The new column to compare to NULL.
      Throws:
      NullPointerException - If the given column is NULL.

    • isNotNull

      public final boolean isNotNull()
      Tells whether the predicate is IS NULL or IS NOT NULL.
      Returns:
      true for IS NOT NULL, false for IS NULL.

    • setNotNull

      public final void setNotNull(boolean notNull)
      Lets indicating which predicate must be used (IS NULL or IS NOT NULL).
      Parameters:
      notNull - true for IS NOT NULL, false for IS NULL.

    • getPosition

      public final TextPosition getPosition()
      Description copied from interface: ADQLObject
      Gets the position of this object/token in the ADQL query.

      By default, no position should be set.

      Specified by:
      getPosition in interface ADQLObject
      Returns:
      Position of this ADQL item in the ADQL query, or NULL if not written originally in the query (for example, if added afterwards).

    • setPosition

      public final void setPosition(TextPosition position)
      Set the position of this IsNull in the given ADQL query string.
      Parameters:
      position - New position of this IsNull.
      Since:
      1.4

    • getCopy

      public ADQLObject getCopy() throws Exception
      Description copied from interface: ADQLObject
      Gets a (deep) copy of this ADQL object.
      Specified by:
      getCopy in interface ADQLObject
      Returns:
      The copy of this ADQL object.
      Throws:
      Exception - If there is any error during the copy.

    • getName

      public String getName()
      Description copied from interface: ADQLObject
      Gets the name of this object in ADQL.
      Specified by:
      getName in interface ADQLObject
      Returns:
      The name of this ADQL object.

    • adqlIterator

      public ADQLIterator adqlIterator()
      Description copied from interface: ADQLObject
      Gets an iterator on the intern ADQL objects.

      Note: The returned iterator is particularly used by a ISearchHandler extension to browse a whole ADQL tree.

      Specified by:
      adqlIterator in interface ADQLObject
      Returns:
      An ADQL objects iterator.
      See Also:

    • toADQL

      public String toADQL()
      Description copied from interface: ADQLObject
      Gets the ADQL expression of this object.
      Specified by:
      toADQL in interface ADQLObject
      Returns:
      The corresponding ADQL expression.