Class ConditionAndOrN

All Implemented Interfaces:
HasSQL, Typed

public class ConditionAndOrN extends Condition
An 'and' or 'or' condition as in WHERE ID=1 AND NAME=? with N operands. Mostly useful for optimisation and preventing stack overflow where generated SQL has tons of conditions.
  • Field Details

    • andOrType

      private final int andOrType
    • expressions

      private final List<Expression> expressions
      Use an ArrayDeque because we primarily insert at the front.
    • added

      private List<Expression> added
      Additional conditions for index only.
    • COMPARE_BY_COST

      private static final Comparator<Expression> COMPARE_BY_COST
  • Constructor Details

  • Method Details

    • getAndOrType

      int getAndOrType()
    • addFirst

      void addFirst(Expression e)
      Add the expression at the beginning of the list.
      Parameters:
      e - the expression
    • needParentheses

      public boolean needParentheses()
      Description copied from class: Expression
      Returns whether this expressions needs to be wrapped in parentheses when it is used as an argument of other expressions.
      Overrides:
      needParentheses in class Expression
      Returns:
      true if it is
    • getUnenclosedSQL

      public StringBuilder getUnenclosedSQL(StringBuilder builder, int sqlFlags)
      Description copied from class: Expression
      Get the SQL statement of this expression. This may not always be the original SQL statement, especially after optimization. Enclosing '(' and ')' are never appended.
      Specified by:
      getUnenclosedSQL in class Expression
      Parameters:
      builder - string builder
      sqlFlags - formatting flags
      Returns:
      the specified string builder
    • createIndexConditions

      public void createIndexConditions(SessionLocal session, TableFilter filter)
      Description copied from class: Expression
      Create index conditions if possible and attach them to the table filter.
      Overrides:
      createIndexConditions in class Expression
      Parameters:
      session - the session
      filter - the table filter
    • getNotIfPossible

      public Expression getNotIfPossible(SessionLocal session)
      Description copied from class: Expression
      If it is possible, return the negated expression. This is used to optimize NOT expressions: NOT ID>10 can be converted to ID<=10. Returns null if negating is not possible.
      Overrides:
      getNotIfPossible in class Expression
      Parameters:
      session - the session
      Returns:
      the negated expression, or null
    • getValue

      public Value getValue(SessionLocal session)
      Description copied from class: Expression
      Return the resulting value for the current row.
      Specified by:
      getValue in class Expression
      Parameters:
      session - the session
      Returns:
      the result
    • optimize

      public Expression optimize(SessionLocal session)
      Description copied from class: Expression
      Try to optimize the expression.
      Specified by:
      optimize in class Expression
      Parameters:
      session - the session
      Returns:
      the optimized expression
    • optimizeMerge

      private boolean optimizeMerge(int i)
    • addFilterConditions

      public void addFilterConditions(TableFilter filter)
      Description copied from class: Expression
      Add conditions to a table filter if they can be evaluated.
      Overrides:
      addFilterConditions in class Expression
      Parameters:
      filter - the table filter
    • mapColumns

      public void mapColumns(ColumnResolver resolver, int level, int state)
      Description copied from class: Expression
      Map the columns of the resolver to expression columns.
      Specified by:
      mapColumns in class Expression
      Parameters:
      resolver - the column resolver
      level - the subquery nesting level
      state - current state for nesting checks, initial value is Expression.MAP_INITIAL
    • setEvaluatable

      public void setEvaluatable(TableFilter tableFilter, boolean b)
      Description copied from class: Expression
      Tell the expression columns whether the table filter can return values now. This is used when optimizing the query.
      Specified by:
      setEvaluatable in class Expression
      Parameters:
      tableFilter - the table filter
      b - true if the table filter can return value
    • updateAggregate

      public void updateAggregate(SessionLocal session, int stage)
      Description copied from class: Expression
      Update an aggregate value. This method is called at statement execution time. It is usually called once for each row, but if the expression is used multiple times (for example in the column list, and as part of the HAVING expression) it is called multiple times - the row counter needs to be used to make sure the internal state is only updated once.
      Specified by:
      updateAggregate in class Expression
      Parameters:
      session - the session
      stage - select stage
    • isEverything

      public boolean isEverything(ExpressionVisitor visitor)
      Description copied from class: Expression
      Check if this expression and all sub-expressions can fulfill a criteria. If any part returns false, the result is false.
      Specified by:
      isEverything in class Expression
      Parameters:
      visitor - the visitor
      Returns:
      if the criteria can be fulfilled
    • getCost

      public int getCost()
      Description copied from class: Expression
      Estimate the cost to process the expression. Used when optimizing the query, to calculate the query plan with the lowest estimated cost.
      Specified by:
      getCost in class Expression
      Returns:
      the estimated cost
    • getSubexpressionCount

      public int getSubexpressionCount()
      Description copied from class: Expression
      Returns count of subexpressions.
      Overrides:
      getSubexpressionCount in class Expression
      Returns:
      count of subexpressions
    • getSubexpression

      public Expression getSubexpression(int index)
      Description copied from class: Expression
      Returns subexpression with specified index.
      Overrides:
      getSubexpression in class Expression
      Parameters:
      index - 0-based index
      Returns:
      subexpression with specified index, may be null