Examples with ExpressionBuilder org.apache.flink.table.planner.expressions.ExpressionBuilder used on opensource projects

Example 1 with ExpressionBuilder

use of org.apache.flink.table.planner.expressions.ExpressionBuilder in project flink by apache.

the class RankLikeAggFunctionBase method orderKeyEqualsExpression.

protected Expression orderKeyEqualsExpression() {
    Expression[] orderKeyEquals = new Expression[orderKeyTypes.length];
    for (int i = 0; i < orderKeyTypes.length; ++i) {
        // pseudo code:
        // if (lastValue_i is null) {
        // if (operand(i) is null) true else false
        // } else {
        // lastValue_i equalTo orderKey(i)
        // }
        Expression lasValue = lastValues[i];
        orderKeyEquals[i] = ifThenElse(isNull(lasValue), ifThenElse(isNull(operand(i)), literal(true), literal(false)), equalTo(lasValue, operand(i)));
    }
    Optional<Expression> ret = Arrays.stream(orderKeyEquals).reduce(ExpressionBuilder::and);
    return ret.orElseGet(() -> literal(true));
}