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Api ReferenceClassesJSONPathBuilder

Last Updated: 3/10/2026

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  • JSONPathBuilder

Class JSONPathBuilder

Type Parameters

  • S
  • O = S

Hierarchy (View Summary)

Index

Constructors

constructor

Methods

at key

Constructors

constructor

Methods

at

  • at<
        I extends number
        | “last”
        | #-${number},
        O2 = null | NonNullable<NonNullable<O>[keyof NonNullable<O> & number]>,

    (
        index: ${[I](#ati)} extends ${any}.${any} | #--${any} ? never : I,
    ): TraversedJSONPathBuilder<S, O2>

    Access an element of a JSON array in a specific location.

    Since there’s no guarantee an element exists in the given array location, the resulting type is always nullable. If you’re sure the element exists, you should use SelectQueryBuilder.$assertType to narrow the type safely.

    See also key to access properties of JSON objects.

    Examples

    await  db. selectFrom('person') . select(eb  =>  eb. ref('nicknames', '->'). at(0). as('primary_nickname') ) . execute()

    The generated SQL (PostgreSQL):

    select "nicknames"->0 as "primary_nickname" from "person"

    Combined with key:

    db. selectFrom('person'). select(eb  =>  eb. ref('experience', '->'). at(0). key('role'). as('first_role'))

    The generated SQL (PostgreSQL):

    select "experience"->0->'role' as "first_role" from "person"

    You can use 'last' to access the last element of the array in MySQL:

    db. selectFrom('person'). select(eb  =>  eb. ref('nicknames', '->$'). at('last'). as('last_nickname'))

    The generated SQL (MySQL):

    select `nicknames`->'$[last]' as `last_nickname` from `person`

    Or '#-1' in SQLite:

    db. selectFrom('person'). select(eb  =>  eb. ref('nicknames', '->>$'). at('#-1'). as('last_nickname'))

    The generated SQL (SQLite):

    select "nicknames"->>'$[#-1]' as `last_nickname` from `person`

    Type Parameters

    • I extends number | “last” | #-${number}
    • O2 = null | NonNullable<NonNullable<O>[keyof NonNullable<O> & number]>

    Parameters

    • index: ${[I](#ati)} extends ${any}.${any} | #--${any} ? never : I

    Returns TraversedJSONPathBuilder<S, O2>

key

  • key<
        K extends string,
        O2 = undefined extends O
            ? null
            | NonNullable<NonNullable<O>[K]>
            : null extends O
                ? NonNullable<NonNullable<O>[K]>
                | null
                : string extends keyof NonNullable<O>
                    ? null | NonNullable<NonNullable<O>[K]>
                    : NonNullable<O>[K],

    (
        key: K,
    ): TraversedJSONPathBuilder<S, O2>

    Access a property of a JSON object.

    If a field is optional, the resulting type will be nullable.

    See also at to access elements of JSON arrays.

    Examples

    db. selectFrom('person'). select(eb  =>  eb. ref('address', '->'). key('city'). as('city'))

    The generated SQL (PostgreSQL):

    select "address"->'city' as "city" from "person"

    Going deeper:

    db. selectFrom('person'). select(eb  =>  eb. ref('profile', '->$'). key('website'). key('url'). as('website_url'))

    The generated SQL (MySQL):

    select `profile`->'$.website.url' as `website_url` from `person`

    Combined with at:

    db. selectFrom('person'). select(eb  =>  eb. ref('profile', '->'). key('addresses'). at(0). key('city'). as('city'))

    The generated SQL (PostgreSQL):

    select "profile"->'addresses'->0->'city' as "city" from "person"

    Type Parameters

    • K extends string
    • O2 = undefined extends O
          ? null
          | NonNullable<NonNullable<O>[K]>
          : null extends O
              ? NonNullable<NonNullable<O>[K]>
              | null
              : string extends keyof NonNullable<O>
                  ? null | NonNullable<NonNullable<O>[K]>
                  : NonNullable<O>[K]

    Parameters

    • key: K

    Returns TraversedJSONPathBuilder<S, O2>

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