litedb-org/LiteDB · error · LiteException

0

0

Error message

Left expression `{left.Source}` returns more than one result. Try use ANY or ALL before operant.

What it means

Thrown by the expression parser during binary-operator construction when the left operand is non-scalar (returns multiple values) and the operator is not prefixed with ALL/ANY. The parser requires multi-value left operands to use quantifiers (ANY/ALL) before comparison operators. This is a LiteException (code 0) thrown at parse time.

Source

Thrown at LiteDB/Document/Expression/Parser/BsonExpressionParser.cs:157

                {
                    order++;
                }
                else
                {
                    // get left/right values to execute operator
                    var left = values.ElementAt(n);
                    var right = values.ElementAt(n + 1);

                    var src = op.Value.Item1;
                    var method = op.Value.Item2;
                    var type = op.Value.Item3;

                    // test left/right scalar
                    var isLeftEnum = op.Key.StartsWith("ALL") || op.Key.StartsWith("ANY");

                    if (isLeftEnum && left.IsScalar) left = ConvertToEnumerable(left);
                    //if (isLeftEnum && left.IsScalar) throw new LiteException(0, $"Left expression `{left.Source}` must return multiples values");
                    if (!isLeftEnum && !left.IsScalar) throw new LiteException(0, $"Left expression `{left.Source}` returns more than one result. Try use ANY or ALL before operant.");
                    if (!isLeftEnum && !right.IsScalar) throw new LiteException(0, $"Left expression `{right.Source}` must return a single value");
                    if (right.IsScalar == false) throw new LiteException(0, $"Right expression `{right.Source}` must return a single value");

                    BsonExpression result;

                    // when operation is AND/OR, use AndAlso|OrElse
                    if (type == BsonExpressionType.And || type == BsonExpressionType.Or)
                    {
                        result = CreateLogicExpression(type, left, right);
                    }
                    else
                    {
                        // method call parameters
                        var args = new List<Expression>();

                        if (method?.GetParameters().FirstOrDefault()?.ParameterType == typeof(Collation))
                        {
                            args.Add(context.Collation);

View on GitHub (pinned to f906a5f850)

Solutions

1. Prefix the comparison with ANY or ALL: `$.tags ANY = 'x'`.
2. Use the helper methods Query.Any / Query.All in the fluent API if building programmatically.
3. Rewrite to use IN or array-contains semantics appropriate to the use case.

Example fix

// before
var docs = col.Query().Where("$.tags = 'x'").ToList();
// after
var docs = col.Query().Where("$.tags ANY = 'x'").ToList();

// Before building the expression, check if left operand is scalar
if (!leftExpr.IsScalar)
    throw new InvalidOperationException("Use ANY/ALL for multi-value left operands.");

static bool NeedsQuantifier(BsonExpression left) => !left.IsScalar;

try { col.Query().Where(whereClause).ToList(); }
catch (LiteException ex) when (ex.Message.Contains("more than one result"))
{ /* add ANY or ALL before the comparison operator */ }

When it happens

Trigger: Writing a query like `$.tags = 'x'` where $.tags is an array field and no ANY/ALL quantifier is used. Comparing a multi-value path expression directly with =, >, <, etc.

Common situations: Querying array fields with direct comparison operators instead of using ANY/ALL. Copying SQL semantics where `array = value` has implicit ANY behavior. Query builder constructing expressions without quantifier awareness.

Related errors

• 0
• 0
• BETWEEN expression need an array with 2 values
• 0
• Unknow token after command

AI-assisted analysis of litedb-org/LiteDB@f906a5f850 (2026-08-13). Data as JSON: /api/errors/2098e36c07bca3c7. Report an issue: GitHub.