Module org.apache.derby.engine
Package org.apache.derby.vti

# Class Restriction.ColumnQualifier

java.lang.Object
org.apache.derby.vti.Restriction
org.apache.derby.vti.Restriction.ColumnQualifier

All Implemented Interfaces:
  `Serializable`

Enclosing class:
  Restriction

public static class Restriction.ColumnQualifier extends Restriction

A simple comparison of a column to a constant value. The comparison has the form:

>      column OP constant

where OP is one of the following:

>       <     =     <=     >      >=    IS NULL    IS NOT NULL

See Also:
  - Serialized Form

- ## Nested Class Summary

  ## Nested classes/interfaces inherited from class org.apache.derby.vti.Restriction

  `Restriction.AND, Restriction.ColumnQualifier, Restriction.OR`

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `static final int`
  `ORDER_OP_EQUALS`
  Ordering operation constant representing '='
  `static final int`
  `ORDER_OP_GREATEROREQUALS`
  Ordering operation constant representing '>='
  `static final int`
  `ORDER_OP_GREATERTHAN`
  Ordering operation constant representing '>'
  `static final int`
  `ORDER_OP_ISNOTNULL`
  Ordering operation constant representing 'IS NOT NULL'
  `static final int`
  `ORDER_OP_ISNULL`
  Ordering operation constant representing 'IS NULL'
  `static final int`
  `ORDER_OP_LESSOREQUALS`
  Ordering operation constant representing '<='
  `static final int`
  `ORDER_OP_LESSTHAN`
  Ordering operation constant representing '<'
  `static final int`
  `ORDER_OP_NOT_EQUALS`
  Ordering operation constant representing '!
  `static final long`
  `serialVersionUID`
  Derby serializes these objects in PreparedStatements

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `ColumnQualifier(String columnName, int comparisonOperator, Object constantOperand)`
  Construct from pieces.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `String`
  `getColumnName()`
  The name of the column being compared.
  `int`
  `getComparisonOperator()`
  The type of comparison to perform.
  `Object`
  `getConstantOperand()`
  Get the constant value to which the column should be compared.
  `String`
  `toSQL()`
  Turn this Restriction into WHERE clause text.

  ### Methods inherited from class java.lang.Object

  `equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- ## Field Details

  - ### serialVersionUID

    public static final long serialVersionUID
    Derby serializes these objects in PreparedStatements
    See Also:
      - Constant Field Values

  - ### ORDER_OP_LESSTHAN

    public static final int ORDER_OP_LESSTHAN
    Ordering operation constant representing '<'
    See Also:
      - Constant Field Values

  - ### ORDER_OP_EQUALS

    public static final int ORDER_OP_EQUALS
    Ordering operation constant representing '='
    See Also:
      - Constant Field Values

  - ### ORDER_OP_LESSOREQUALS

    public static final int ORDER_OP_LESSOREQUALS
    Ordering operation constant representing '<='
    See Also:
      - Constant Field Values

  - ### ORDER_OP_GREATERTHAN

    public static final int ORDER_OP_GREATERTHAN
    Ordering operation constant representing '>'
    See Also:
      - Constant Field Values

  - ### ORDER_OP_GREATEROREQUALS

    public static final int ORDER_OP_GREATEROREQUALS
    Ordering operation constant representing '>='
    See Also:
      - Constant Field Values

  - ### ORDER_OP_ISNULL

    public static final int ORDER_OP_ISNULL
    Ordering operation constant representing 'IS NULL'
    See Also:
      - Constant Field Values

  - ### ORDER_OP_ISNOTNULL

    public static final int ORDER_OP_ISNOTNULL
    Ordering operation constant representing 'IS NOT NULL'
    See Also:
      - Constant Field Values

  - ### ORDER_OP_NOT_EQUALS

    public static final int ORDER_OP_NOT_EQUALS
    Ordering operation constant representing '!='
    See Also:
      - Constant Field Values

- ## Constructor Details

  - ### ColumnQualifier

    public ColumnQualifier(String columnName, int comparisonOperator, Object constantOperand)

    Construct from pieces.

    Parameters:
      `columnName` - Name of column as declared in the CREATE FUNCTION statement.
      `comparisonOperator` - One of the ORDER_OP constants.
      `constantOperand` - Constant value to which the column should be compared.

- ## Method Details

  - ### getColumnName

    public String getColumnName()

    The name of the column being compared.

    Returns:
      the name of the column being compared

  - ### getComparisonOperator

    public int getComparisonOperator()

    The type of comparison to perform. This is one of the ORDER_OP constants defined above.

    Returns:
      an ORDER_OP representing the type of comparison to perform

  - ### getConstantOperand

    public Object getConstantOperand()

    Get the constant value to which the column should be compared. The constant value must be an Object of the Java type which corresponds to the SQL type of the column. The column's SQL type was declared in the CREATE FUNCTION statement. The mapping of SQL types to Java types is defined in table 4 of chapter 14 of the original JDBC 1 specification (dated 1996). Bascially, these are the Java wrapper values you would expect. For instance, SQL INT maps to java.lang.Integer, SQL CHAR maps to java.lang.String, etc.. This object will be null if the comparison operator is ORDER_OP_ISNULL or ORDER_OP_ISNOTNULL.

    Returns:
      the constant with which the column is being compared

  - ### toSQL

    public String toSQL()
    Turn this Restriction into WHERE clause text.
    Specified by:
      `toSQL` in class `Restriction`
    Returns:
      this Restriction as WHERE clause text