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

Example 1 with SqlAggFunctionVisitor

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

the class OverConvertRule method convert.

@Override
public Optional<RexNode> convert(CallExpression call, ConvertContext context) {
    List<Expression> children = call.getChildren();
    if (call.getFunctionDefinition() == BuiltInFunctionDefinitions.OVER) {
        FlinkTypeFactory typeFactory = context.getTypeFactory();
        Expression agg = children.get(0);
        FunctionDefinition def = ((CallExpression) agg).getFunctionDefinition();
        boolean isDistinct = BuiltInFunctionDefinitions.DISTINCT == def;
        SqlAggFunction aggFunc = agg.accept(new SqlAggFunctionVisitor(context.getRelBuilder()));
        RelDataType aggResultType = typeFactory.createFieldTypeFromLogicalType(fromDataTypeToLogicalType(((ResolvedExpression) agg).getOutputDataType()));
        // assemble exprs by agg children
        List<RexNode> aggExprs = agg.getChildren().stream().map(child -> {
            if (isDistinct) {
                return context.toRexNode(child.getChildren().get(0));
            } else {
                return context.toRexNode(child);
            }
        }).collect(Collectors.toList());
        // assemble order by key
        Expression orderKeyExpr = children.get(1);
        Set<SqlKind> kinds = new HashSet<>();
        RexNode collationRexNode = createCollation(context.toRexNode(orderKeyExpr), RelFieldCollation.Direction.ASCENDING, null, kinds);
        ImmutableList<RexFieldCollation> orderKey = ImmutableList.of(new RexFieldCollation(collationRexNode, kinds));
        // assemble partition by keys
        List<RexNode> partitionKeys = children.subList(4, children.size()).stream().map(context::toRexNode).collect(Collectors.toList());
        // assemble bounds
        Expression preceding = children.get(2);
        boolean isPhysical = fromDataTypeToLogicalType(((ResolvedExpression) preceding).getOutputDataType()).is(LogicalTypeRoot.BIGINT);
        Expression following = children.get(3);
        RexWindowBound lowerBound = createBound(context, preceding, SqlKind.PRECEDING);
        RexWindowBound upperBound = createBound(context, following, SqlKind.FOLLOWING);
        // build RexOver
        return Optional.of(context.getRelBuilder().getRexBuilder().makeOver(aggResultType, aggFunc, aggExprs, partitionKeys, orderKey, lowerBound, upperBound, isPhysical, true, false, isDistinct));
    }
    return Optional.empty();
}