Class Selects


  • public class Selects
    extends Object
    A factory class to create select expressions.
    Version:
    2.0
    Author:
    Nicklas
    Last modified
    $Date: 2015-04-21 09:59:42 +0200 (ti, 21 apr 2015) $
    • Field Detail

      • ALIAS_REGEXP

        public static final Pattern ALIAS_REGEXP
        An alias can only contain the characters a-z, A-Z or 0-9.
    • Constructor Detail

      • Selects

        public Selects()
    • Method Detail

      • expression

        public static final Select expression​(Expression e1,
                                              String alias)
                                       throws InvalidDataException
        Same as expression(e1, alias, false).
        Parameters:
        e1 - The expression to select. Null is not allowed
        alias - The alias to give the expression. Only characters a-z, A-Z and 0-9 are allowed. Null is allowed.
        Returns:
        A selection query element
        Throws:
        InvalidDataException - If the required parameter is null or if illegal characters is used in alias
        See Also:
        expression(Expression, String, boolean)
      • expression

        public static final Select expression​(Expression e1,
                                              String alias,
                                              boolean useInDistinctCount)
                                       throws InvalidDataException
        Create a selection from an expression, optionally giving it an alias. The alias can be used when getting the result to find the column index. See SqlResultIterator.getIndex(String).
        SELECT <expression> AS <alias>
        FROM ...
                

        The useInDistinctCount parameter affects the Query.count(DbControl) method, if the Query.setDistinct(boolean) has been set to true. In this case only expressions which has been created for use with the distinct function are used in the selection list:

        SELECT COUNT(DISTINCT <expression>)
        FROM ...
                

        Parameters:
        e1 - The expression to select
        alias - The alias to give the expression
        useInDistinctCount - If the expression should be used when counting distinct values
        Returns:
        A selection query element
        Throws:
        InvalidDataException - If the expression is null or if the alias contains invalid characters