HelixDB Docs

@tags: errors, error-codes, debugging, troubleshooting, validation, compile-errors, query, query-errors

E101: Unknown Node Type

Reference a node type that is not defined in schema.hx.

Example

Schema:

// no types defined

Query:

QUERY getUser(id: ID) =>
    user <- N<User>(id)
    RETURN user

Solution

Define the node type User in schema.hx.

Schema:

N::User {
    // fields
}

E102: Unknown Edge Type

Reference an edge type that is not defined in schema.hx.

Example

Schema:

N::User {
    // fields
}

N::Post {
    // fields
}

Query:

QUERY getUsersPosts(id: ID) =>
    posts <- N<User>(id)::Out<Posted>
    RETURN posts

Solution

Define the edge type Posted in schema.hx.

Schema:

N::User {
    // fields
}

N::Post {
// fields
}

E::Posted {
    From: User,
    To: Post,
}

E103: Unknown Vector Type

Reference a vector type that is not defined in schema.hx.

Example

Schema:

// no types defined

Query:

QUERY search(query: String) =>
    results <- SearchV<Document>(Embed(query), 10)
    RETURN results

Solution

Define the vector type Document in schema.hx.

Schema:

V::Document {
    // fields
}

E105: Invalid Identifier

Use an invalid identifier in query.hx.

Example

Out is a reserved keyword so it cannot be used as a variable or a parameter name.

Query:

QUERY getUser(id: ID) =>
    Out <- N<User>(id)
    RETURN Out

QUERY getUser(Out: ID) =>
    user <- N<User>(Out)
    RETURN user

Solution

Rename the variable or parameter to a valid identifier.

Query:

QUERY getUser(id: ID) =>
    user <- N<User>(id)
    RETURN user

QUERY getUser(id: ID) =>
    user <- N<User>(id)
    RETURN user

E202: Field Not in Schema

Reference a field that is not defined in schema.hx for a given item type.

Example

The field username is not defined in schema.hx for the User item type.

Schema:

N::User {
    age: U32,
}

Query:

QUERY getUser(id: ID) =>
    user <- N<User>(id)
    RETURN user::{username}

Solution

Define the field username in schema.hx for the User item type.

Schema:

N::User {
    username: String,
    age: U32,
}

E204: Reserved Field Name

Use a reserved field name in schema.hx or query.hx.

Example

The field id is a reserved field name for any item type.

Schema:

N::User {
    id: String,
}

Solution

Rename the field to a valid identifier.

Schema:

N::User {
    github_id: String,
}

E205: Type Mismatch

Occurs when the type of a value you’re providing doesn’t match the expected field type defined in schema.hx.

Example

Schema:

N::User {
    someField: String,
}

Query:

QUERY addUser(someField: U32) =>
    user <- AddN<User>({someField: someField})
    RETURN user

Solution

Change type of someField to String or U32.

Schema:

N::User {
    someField: U32,
}

Query:

QUERY addUser(someField: U32) =>
    user <- AddN<User>({someField: someField})
    RETURN user

E207: Invalid Edge Type for Item

Use an edge type that exists in schema.hx but is not valid for the specific item type you’re working with.

Example

In this example, the Created edge exists. However, it goes from User to Post, not from Post to User. Therefore, it is not valid for an Out step from a Post node.

Schema:

N::User {
    // Fields
}

N::Post {
    // Fields
}

E::Created {
    From: User,
    To: Post,
}

Query:

Query getUserFromPost(postId: ID) =>
    user <- N<Post>(postId)::Out<Created>
    RETURN user

Solution

Change the traversal to use the In step instead of the Out step.

Query:

Query getUserFromPost(postId: ID) =>
    user <- N<Post>(postId)::In<Created>

E301: Variable Not in Scope

Reference a variable that is not currently in scope or has not been declared.

Example

The variable userId is not declared.

Query:

Query getUser() =>
    user <- N<User>(userId)
    RETURN user

Solution

Declare the variable userId as a parameter before using it.

Query:

Query getUser(userId: ID) =>
    user <- N<User>(userId)
    RETURN user

E302: Variable Previously Declared

Declare a variable that has already been declared in the current scope.

Example

In this example, the variable userId is declared twice.

Query:

Query getUser(userId: ID) =>
    userId <- N<User>(userId)::ID
    RETURN userId

Solution

Use a different variable name.

Query:

Query getUser(userId: ID) =>
    user_id <- N<User>(userId)::ID
    RETURN user_id

E304: Missing Item Type

An item type is required but not provided in your query.

Example

The User item type is required but not provided.

Query:

Query getUser(userId: ID) =>
    user <- N(userId)
    RETURN user

Query getUser(userId: ID) =>
    user <- N<User>(userId)::Out
    RETURN user

Solution

Specify the required item type within the < and > brackets after the traversal step in your query.

Query:

Query getUser(userId: ID) =>
    user <- N<User>(userId)::Out<Knows>
    RETURN user

E305: Missing Parameter

A required parameter is missing from a function call or operation.

Example

The SearchV function is called without the k parameter which is required to limit the number of results.

Query:

Query searchUsers(vector: [F64]) =>
    users <- SearchV<Document>(vector)
    RETURN users

Solution

Provide all required parameters for functions and operations.

Query:

Query searchUsers(vector: [F64]) =>
    users <- SearchV<Document>(vector, 10)
    RETURN users

E401: MCP Single Value Requirement

An MCP (Model Context Protocol) query returns multiple values when only a single value is expected.

Example

The MCP query returns multiple users, but MCP expects a single value.

Query:

#[mcp]
Query getUsers(userId: ID, postId: ID) =>
    user <- N<User>(userId)
    post <- N<Post>(postId)
    RETURN user, post

Solution

Ensure MCP queries return exactly one value.

Query:

#[mcp]
Query getUsers(userId: ID, postId: ID) =>
    user <- N<User>(userId)
    post <- N<Post>(postId)
    RETURN user

E501: Invalid Date

Provide a date value that cannot be parsed or is in an invalid format.

Example

The date value "2023-99-99" is invalid and cannot be parsed.

Schema:

N::Event {
    date: Date,
}

Query:

Query addEvent() =>
    AddN<Event>({date: "2023-99-99"})

Solution

Ensure the date value is in the correct format.

Query:

Query addEvent() =>
    AddN<Event>({date: "2023-01-01"})

E601: Invalid Traversal

Attempt to perform a malformed traversal. Note: This error is not currently emitted by the compiler.

Example

Query:

Query getUser() =>
    user <- N()

Solution

Query:

Query getUser() =>
    user <- N<User>
    RETURN user

E602: Invalid Step

Use a step that is not valid in the current context.

Example

The OutE<Knows> step results in edges, but the Out step can only be used on nodes.

Schema:

N::User {
    // fields
}

E::Knows {
    From: User,
    To: User,
}

Query:

Query getUser() =>
    user <- N<User>::OutE<Knows>::Out<Knows>
    RETURN user

Solution

Query:

Query getUser() =>
    user <- N<User>::Out<Knows>::Out<Knows>
    RETURN user

E604: Update Restriction

Performing an update operation on something other than nodes or edges.

Example

The update step is used on a vector type which is not allowed yet.

Query:

V::Vector {
    field1: String,
}

E611: Missing To ID

Create an edge without specifying the target node ID.

Example

The AddE step is used without specifying the To parameter.

Query:

Query addEdge(from: ID, to: ID) =>
    AddE<Follows>::From(from)

Solution

Provide both From and To node IDs when creating edges.

Query:

Query addEdge(from: ID, to: ID) =>
    AddE<Follows>::From(from)::To(to)

E612: Missing From ID

Create an edge without specifying the source node ID.

Example

The AddE step is used without specifying the From parameter.

Query:

Query addEdge(to: ID) =>
    AddE<Follows>::To(to)

Solution

Provide both From and To node IDs when creating edges.

Query:

Query addEdge(from: ID, to: ID) =>
    AddE<Follows>::From(from)::To(to)

E621: Invalid Boolean Comparison

Apply a boolean comparison operation to a type that doesn’t support it.

Example

Schema:

N::User {
    name: String,
}

Query:

Query getUser(user1: ID, user2: ID) =>
    user1 <- N<User>(user1)
    user2 <- N<User>(user2)
    is_eq <- user1::EQ(user2)
    RETURN is_eq

Solution

Ensure boolean operations are used on values that result in primitive types like booleans, numbers, or strings.

Query:

Query getUser(user1: ID, user2: ID) =>
    user1_name <- N<User>(user1)::{name}
    user2_name <- N<User>(user2)::{name}
    is_eq <- user1_name::EQ(user2_name)
    RETURN is_eq

E622: Type Mismatch in Comparison

Compare a property with a value of a different type.

Example

Schema:

N::User {
    name: String,
    age: I64,
}

Query:

Query getUser(user: ID) =>
    user <- N<User>(user)
    is_eq <- user::{name}::EQ(25)
    RETURN is_eq

Solution

Query:

Query getUser(user: ID) =>
    user <- N<User>(user)
    is_eq <- user::{age}::EQ(25)
    RETURN is_eq

E631: Incomplete Range

Define a range without both start and end values.

Example

Query:

Query getUser() =>
    subset_of_users <- N<User>::RANGE(0)
    RETURN subset_of_users

Solution

Query:

Query getUser() =>
    subset_of_users <- N<User>::RANGE(0, 100)
    RETURN subset_of_users

E632: Invalid Range Order

The start value of a range is greater than or equal to the end value. This error is only emitted by the compiler when both start and end values are provided as literals. A runtime error will be emitted if the range is not valid at runtime.

Example

The start value is greater than the end value.

Query:

Query getUser() =>
    subset_of_users <- N<User>::RANGE(100, 10)
    RETURN subset_of_users

Solution

Ensure range start value is less than end value.

Query:

Query getUser() =>
    subset_of_users <- N<User>::RANGE(10, 100)
    RETURN subset_of_users

E633: Non-Integer Range Index

Use a non-integer value as an index in a range operation.

Example

The range index is a float value which is not allowed.

Query:

Query getUser() =>
    subset_of_users <- N<User>::RANGE(1.5, 4.9)
    RETURN subset_of_users

Query getUser(end: F32) =>
    subset_of_users <- N<User>::RANGE(0, end)
    RETURN subset_of_users

Solution

Use integer values for range indices or set variable types to integer types.

Query:

Query getUser() =>
    subset_of_users <- N<User>::RANGE(1, 5)
    RETURN subset_of_users
    
Query getUser(end: I64) =>
    subset_of_users <- N<User>::RANGE(0, end)
    RETURN subset_of_users

E641: Closure Position Restriction

Place a closure operation in a position other than the last step of a traversal.

Example

The closure is not at the end of the traversal.

Query:

Query getUser(userId: ID) =>
    user <- N<User>(userId)
    RETURN user::|u|{
                userID: u::ID
            }::Out<Knows>

Solution

Move the closure to the last step of the traversal.

Query:

Query getUser(userId: ID) =>
    user <- N<User>(userId)
    out_users <- user::Out<Knows>
    RETURN out_users, user::|u|{
                            userID: u::ID
                        }

E642: Object Position Restriction

Place an object operation in a position other than the last step of a traversal.

Example

The object is not at the end of the traversal.

Query:

Query getUser(userId: ID) =>
    user <- N<User>(userId)
    RETURN user::{
                userID: ID
            }::Out<Knows>

Solution

Move the object to the last step of the traversal.

Query:

Query getUser(userId: ID) =>
    user <- N<User>(userId)
    out_users <- user::Out<Knows>
    RETURN out_users, user::{
                            userID: ID
                        }::Out<Knows>

E643: Field Previously Excluded

Access or include a field that has been previously excluded in the traversal.

Example

The email field is excluded in the traversal, but is being included.

Query:

Query getUser(userId: ID) =>
    user <- N<User>(userId)::!{email}
    RETURN user::{email}

Solution

Remove the exclusion or access the field after the exclusion.

Query:

Query getUser(userId: ID) =>
    user <- N<User>(userId)
    RETURN user::{email}

E644: Exclude Position Restriction

Place an exclude operation in a position other than the last step of a traversal or the step before an object remapping or closure remapping step.

Example

The exclude step is used before the Out<Knows> step which is not allowed.

Query:

Query getUser(userId: ID) =>
    users <- N<User>(userId)::!{email}::Out<Knows>
    RETURN users

Solution

Move the exclude step to the last step of the traversal or the step before an object remapping or closure remapping step.

Query:

Query getUser(userId: ID) =>
    users <- N<User>(userId)::Out<Knows>::!{email}
    RETURN users

E645

Define an object remapping with no fields.

Example

Schema:

N::User {
    name: String,
}

Query:

Query getUser(userId: ID) =>
    user <- N<User>(userId)
    RETURN user::{}

Solution

Query:

Query getUser(userId: ID) =>
    user <- N<User>(userId)
    RETURN user::{name}

E651: Non-Iterable Variable

Use a non-iterable variable in an iteration context.

Example

The parameter name is not iterable, so it cannot be used in an iteration context.

Query:

Query addUser(name: String) =>
    FOR n IN name {
        AddN<User>({name: n})
    }
    RETURN "User added"

Solution

Ensure variables used in iterations are collections or arrays.

Query:

Query addUser(names: [String]) =>
    FOR n IN names {
        AddN<User>({name: n})
    }
    RETURN "Users added"

E652: Invalid Field Access

Access a field that doesn’t exist on the inner type of an iterable variable.

Example

The nonexistent_field field doesn’t exist on the inner type of the userData iterable variable.

Query:

Query addUser(userData: [{name: String, age: I64}]) =>
    FOR { name, age, nonexistent_field } IN userData {
        AddN<User>({name: name, age: age})
    }
    RETURN "Users added"

Solution

Ensure to only access fields that exist on the inner type.

Query:

Query addUser(userData: [{name: String, age: I64}]) =>
    FOR { name, age } IN userData {
        AddN<User>({name: name, age: age})
    }
    RETURN "Users added"

E653: Non-Object Inner Type

The inner type of an iterable variable is not an object type, preventing field access or object destructuring.

Example

The names variable contains strings, not objects, so field access is not allowed.

Query:

Query addUsers(names: [String]) =>
    FOR {name} In names {
        AddN<User>({name: name})
    }
    RETURN "Users added"

Solution

Ensure iterable contains object types for field access.

Query:

Query addUsers(names: [String]) =>
    FOR name IN names {
        AddN<User>({name: name})
    }
    RETURN "Users added"

Query addUsers(names: [{name: String}]) =>
    FOR {name} IN names {
        AddN<User>({name: name})
    }
    RETURN "Users added"

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​E101: Unknown Node Type

​Example

​Solution

​E102: Unknown Edge Type

​Example

​Solution

​E103: Unknown Vector Type

​Example

​Solution

​E105: Invalid Identifier

​Example

​Solution

​E202: Field Not in Schema

​Example

​Solution

​E204: Reserved Field Name

​Example

​Solution

​E205: Type Mismatch

​Example

​Solution

​E207: Invalid Edge Type for Item

​Example

​Solution

​E301: Variable Not in Scope

​Example

​Solution

​E302: Variable Previously Declared

​Example

​Solution

​E304: Missing Item Type

​Example

​Solution

​E305: Missing Parameter

​Example

​Solution

​E401: MCP Single Value Requirement

​Example

​Solution

​E501: Invalid Date

​Example

​Solution

​E601: Invalid Traversal

​Example

​Solution

​E602: Invalid Step

​Example

​Solution

​E604: Update Restriction

​Example

​E611: Missing To ID

​Example

​Solution

​E612: Missing From ID

​Example

​Solution

​E621: Invalid Boolean Comparison

​Example

​Solution

​E622: Type Mismatch in Comparison

​Example

​Solution

​E631: Incomplete Range

​Example

​Solution

​E632: Invalid Range Order

​Example

​Solution

​E633: Non-Integer Range Index

​Example

​Solution

​E641: Closure Position Restriction

​Example

​Solution

​E642: Object Position Restriction

​Example

E101: Unknown Node Type

Example

Solution

E102: Unknown Edge Type

Example

Solution

E103: Unknown Vector Type

Example

Solution

E105: Invalid Identifier

Example

Solution

E202: Field Not in Schema

Example

Solution

E204: Reserved Field Name

Example

Solution

E205: Type Mismatch

Example

Solution

E207: Invalid Edge Type for Item

Example

Solution

E301: Variable Not in Scope

Example

Solution

E302: Variable Previously Declared

Example

Solution

E304: Missing Item Type

Example

Solution

E305: Missing Parameter

Example

Solution

E401: MCP Single Value Requirement

Example

Solution

E501: Invalid Date

Example

Solution

E601: Invalid Traversal

Example

Solution

E602: Invalid Step

Example

Solution

E604: Update Restriction

Example

E611: Missing To ID

Example

Solution

E612: Missing From ID

Example

Solution

E621: Invalid Boolean Comparison

Example

Solution

E622: Type Mismatch in Comparison

Example

Solution

E631: Incomplete Range

Example

Solution

E632: Invalid Range Order

Example

Solution

E633: Non-Integer Range Index

Example

Solution

E641: Closure Position Restriction

Example

Solution

E642: Object Position Restriction

Example

Solution

E643: Field Previously Excluded

Example

Solution