Class SqlSnapshot

  • All Implemented Interfaces:
    java.lang.Cloneable

    public class SqlSnapshot
    extends SqlCall
    Parse tree node for "FOR SYSTEM_TIME AS OF" temporal clause.
    • Method Detail

      • getTableRef

        public SqlNode getTableRef()
      • getPeriod

        public SqlNode getPeriod()
      • setOperand

        public void setOperand​(int i,
                               SqlNode operand)
        Description copied from class: SqlCall
        Changes the value of an operand. Allows some rewrite by SqlValidator; use sparingly.
        Overrides:
        setOperand in class SqlCall
        Parameters:
        i - Operand index
        operand - Operand value
      • 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 SqlCall
        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