Examples with IfExpression com.facebook.presto.sql.tree.IfExpression used on opensource projects

Example 1 with IfExpression

use of com.facebook.presto.sql.tree.IfExpression in project presto by prestodb.

the class AstBuilder method visitFunctionCall.

@Override
public Node visitFunctionCall(SqlBaseParser.FunctionCallContext context) {
    Optional<Expression> filter = visitIfPresent(context.filter(), Expression.class);
    Optional<Window> window = visitIfPresent(context.over(), Window.class);
    Optional<OrderBy> orderBy = Optional.empty();
    if (context.ORDER() != null) {
        orderBy = Optional.of(new OrderBy(visit(context.sortItem(), SortItem.class)));
    }
    QualifiedName name = getQualifiedName(context.qualifiedName());
    boolean distinct = isDistinct(context.setQuantifier());
    boolean ignoreNulls = context.nullTreatment() != null && context.nullTreatment().IGNORE() != null;
    if (name.toString().equalsIgnoreCase("if")) {
        check(context.expression().size() == 2 || context.expression().size() == 3, "Invalid number of arguments for 'if' function", context);
        check(!window.isPresent(), "OVER clause not valid for 'if' function", context);
        check(!distinct, "DISTINCT not valid for 'if' function", context);
        check(!filter.isPresent(), "FILTER not valid for 'if' function", context);
        Expression elseExpression = null;
        if (context.expression().size() == 3) {
            elseExpression = (Expression) visit(context.expression(2));
        }
        return new IfExpression(getLocation(context), (Expression) visit(context.expression(0)), (Expression) visit(context.expression(1)), elseExpression);
    }
    if (name.toString().equalsIgnoreCase("nullif")) {
        check(context.expression().size() == 2, "Invalid number of arguments for 'nullif' function", context);
        check(!window.isPresent(), "OVER clause not valid for 'nullif' function", context);
        check(!distinct, "DISTINCT not valid for 'nullif' function", context);
        check(!filter.isPresent(), "FILTER not valid for 'nullif' function", context);
        return new NullIfExpression(getLocation(context), (Expression) visit(context.expression(0)), (Expression) visit(context.expression(1)));
    }
    if (name.toString().equalsIgnoreCase("coalesce")) {
        check(context.expression().size() >= 2, "The 'coalesce' function must have at least two arguments", context);
        check(!window.isPresent(), "OVER clause not valid for 'coalesce' function", context);
        check(!distinct, "DISTINCT not valid for 'coalesce' function", context);
        check(!filter.isPresent(), "FILTER not valid for 'coalesce' function", context);
        return new CoalesceExpression(getLocation(context), visit(context.expression(), Expression.class));
    }
    if (name.toString().equalsIgnoreCase("try")) {
        check(context.expression().size() == 1, "The 'try' function must have exactly one argument", context);
        check(!window.isPresent(), "OVER clause not valid for 'try' function", context);
        check(!distinct, "DISTINCT not valid for 'try' function", context);
        check(!filter.isPresent(), "FILTER not valid for 'try' function", context);
        return new TryExpression(getLocation(context), (Expression) visit(getOnlyElement(context.expression())));
    }
    if (name.toString().equalsIgnoreCase("$internal$bind")) {
        check(context.expression().size() >= 1, "The '$internal$bind' function must have at least one arguments", context);
        check(!window.isPresent(), "OVER clause not valid for '$internal$bind' function", context);
        check(!distinct, "DISTINCT not valid for '$internal$bind' function", context);
        check(!filter.isPresent(), "FILTER not valid for '$internal$bind' function", context);
        int numValues = context.expression().size() - 1;
        List<Expression> arguments = context.expression().stream().map(this::visit).map(Expression.class::cast).collect(toImmutableList());
        return new BindExpression(getLocation(context), arguments.subList(0, numValues), arguments.get(numValues));
    }
    return new FunctionCall(getLocation(context), getQualifiedName(context.qualifiedName()), window, filter, orderBy, distinct, ignoreNulls, visit(context.expression(), Expression.class));
}

Example 2 with IfExpression

use of com.facebook.presto.sql.tree.IfExpression in project presto by prestodb.

the class TestEqualityInference method testExpressionsThatMayReturnNullOnNonNullInput.

@Test
public void testExpressionsThatMayReturnNullOnNonNullInput() throws Exception {
    List<Expression> candidates = ImmutableList.of(// try_cast
    new Cast(nameReference("b"), "BIGINT", true), new FunctionCall(QualifiedName.of("try"), ImmutableList.of(nameReference("b"))), new NullIfExpression(nameReference("b"), number(1)), new IfExpression(nameReference("b"), number(1), new NullLiteral()), new DereferenceExpression(nameReference("b"), "x"), new InPredicate(nameReference("b"), new InListExpression(ImmutableList.of(new NullLiteral()))), new SearchedCaseExpression(ImmutableList.of(new WhenClause(new IsNotNullPredicate(nameReference("b")), new NullLiteral())), Optional.empty()), new SimpleCaseExpression(nameReference("b"), ImmutableList.of(new WhenClause(number(1), new NullLiteral())), Optional.empty()), new SubscriptExpression(new ArrayConstructor(ImmutableList.of(new NullLiteral())), nameReference("b")));
    for (Expression candidate : candidates) {
        EqualityInference.Builder builder = new EqualityInference.Builder();
        builder.extractInferenceCandidates(equals(nameReference("b"), nameReference("x")));
        builder.extractInferenceCandidates(equals(nameReference("a"), candidate));
        EqualityInference inference = builder.build();
        List<Expression> equalities = inference.generateEqualitiesPartitionedBy(matchesSymbols("b")).getScopeStraddlingEqualities();
        assertEquals(equalities.size(), 1);
        assertTrue(equalities.get(0).equals(equals(nameReference("x"), nameReference("b"))) || equalities.get(0).equals(equals(nameReference("b"), nameReference("x"))));
    }
}

Example 3 with IfExpression

use of com.facebook.presto.sql.tree.IfExpression in project presto by prestodb.

the class TestSqlParser method testIf.

@Test
public void testIf() {
    assertExpression("if(true, 1, 0)", new IfExpression(new BooleanLiteral("true"), new LongLiteral("1"), new LongLiteral("0")));
    assertExpression("if(true, 3, null)", new IfExpression(new BooleanLiteral("true"), new LongLiteral("3"), new NullLiteral()));
    assertExpression("if(false, null, 4)", new IfExpression(new BooleanLiteral("false"), new NullLiteral(), new LongLiteral("4")));
    assertExpression("if(false, null, null)", new IfExpression(new BooleanLiteral("false"), new NullLiteral(), new NullLiteral()));
    assertExpression("if(true, 3)", new IfExpression(new BooleanLiteral("true"), new LongLiteral("3"), null));
    assertInvalidExpression("IF(true)", "Invalid number of arguments for 'if' function");
    assertInvalidExpression("IF(true, 1, 0) FILTER (WHERE true)", "FILTER not valid for 'if' function");
    assertInvalidExpression("IF(true, 1, 0) OVER()", "OVER clause not valid for 'if' function");
}