Class SqlIntervalLiteral

  • All Implemented Interfaces:
    java.lang.Cloneable

    public class SqlIntervalLiteral
    extends SqlLiteral
    A SQL literal representing a time interval.

    Examples:

    • INTERVAL '1' SECOND
    • INTERVAL '1:00:05.345' HOUR
    • INTERVAL '3:4' YEAR TO MONTH

    YEAR/MONTH intervals are not implemented yet.

    The interval string, such as '1:00:05.345', is not parsed yet.

    • Method Detail

      • unparse

        public void unparse​(SqlWriter writer,
                            int leftPrec,
                            int rightPrec)
        Description copied from class: SqlNode
        Writes a SQL representation of this node to a writer.

        The leftPrec and rightPrec parameters give us enough context to decide whether we need to enclose the expression in parentheses. For example, we need parentheses around "2 + 3" if preceded by "5 *". This is because the precedence of the "*" operator is greater than the precedence of the "+" operator.

        The algorithm handles left- and right-associative operators by giving them slightly different left- and right-precedence.

        If SqlWriter.isAlwaysUseParentheses() is true, we use parentheses even when they are not required by the precedence rules.

        For the details of this algorithm, see SqlCall.unparse(org.apache.calcite.sql.SqlWriter, int, int).

        Overrides:
        unparse in class SqlLiteral
        Parameters:
        writer - Target writer
        leftPrec - The precedence of the SqlNode immediately preceding this node in a depth-first scan of the parse tree
        rightPrec - The precedence of the SqlNode immediately
      • signum

        public int signum()
        Description copied from class: SqlLiteral
        Returns sign of value.
        Overrides:
        signum in class SqlLiteral
        Returns:
        -1, 0 or 1