4 ORM Operations

MongoDB

1 Quickstart

2 BSON

3 Basic Operations

4 ORM Operations

5 Other

4 ORM Operations

4.1 Dictionaries

4.2 Structures

On this page:

4.1Dictionaries

4.2Structures

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4ORM Operations🔗 i

(require db/mongodb/orm/main ) package: mongodb

An "ORM" style API is built on the basic Mongo operations.

4.1Dictionaries🔗 i

(require db/mongodb/orm/dict ) package: mongodb

A Mongo dictionary is a dictionary backed by Mongo.

procedure
( create-mongo-dict col)→mongo-dict?
col:string?

Creates a new Mongo dictionary in the col collection of the (current-mongo-db ) database.

procedure
( mongo-dict-query colquery)→(sequenceofmongo-dict? )
col:string?
query:bson-document/c

Queries the collection and returns Mongo dictionaries.

procedure
( mongo-dict? x)→boolean?
x:any/c

A test for Mongo dictionaries.

parameter
( current-mongo-db )→(or/c false/c mongo-db? )
(current-mongo-db db)→void?
db:(or/c false/c mongo-db? )

The database used in Mongo dictionary operations.

procedure
( mongo-dict-ref mdkey[fail])→any/c
md:mongo-dict?
key:symbol?
fail:any/c =bson-null

Like dict-ref but for Mongo dictionaries, returns bson-null by default on errors or missing values.

procedure
( mongo-dict-set! mdkeyval)→void
md:mongo-dict?
key:symbol?
val:any/c

Like dict-set! but for Mongo dictionaries.

procedure
( mongo-dict-remove! mdkey)→void
md:mongo-dict?
key:symbol?

Like dict-remove! but for Mongo dictionaries.

procedure
( mongo-dict-count md)→exact-nonnegative-integer?
md:mongo-dict?

Like dict-count but for Mongo dictionaries.

procedure
( mongo-dict-inc! mdkey[amt])→void
md:mongo-dict?
key:symbol?
amt:number? =1

Increments key’s value by amt atomically.

procedure
( mongo-dict-push! mdkeyval)→void
md:mongo-dict?
key:symbol?
val:any/c

Pushes a value onto the sequence atomically.

procedure
( mongo-dict-append! mdkeyvals)→void
md:mongo-dict?
key:symbol?
vals:sequence?

Pushes a sequence of values onto the sequence atomically.

procedure
( mongo-dict-set-add! mdkeyval)→void
md:mongo-dict?
key:symbol?
val:any/c

Adds a value to the sequence if it is not present atomically.

procedure
( mongo-dict-set-add*! mdkeyvals)→void
md:mongo-dict?
key:symbol?
vals:sequence?

Adds a sequence of values to the sequence if they are not present atomically.

procedure
( mongo-dict-pop! mdkey)→void
md:mongo-dict?
key:symbol?

Pops a value off the sequence atomically.

procedure
( mongo-dict-shift! mdkey)→void
md:mongo-dict?
key:symbol?

Shifts a value off the sequence atomically.

procedure
( mongo-dict-pull! mdkeyval)→void
md:mongo-dict?
key:symbol?
val:any/c

Remove a value to the sequence if it is present atomically.

procedure
( mongo-dict-pull*! mdkeyvals)→void
md:mongo-dict?
key:symbol?
vals:sequence?

Removes a sequence of values to the sequence if they are present atomically.

4.2Structures🔗 i

(require db/mongodb/orm/struct ) package: mongodb

define-mongo-struct is a macro to create some convenience functions for Mongo dictionaries.

syntax
( define-mongo-struct structcollection
([fieldopt...]
...))

opt = #:required
| #:immutable
| #:ref
| #:set!
| #:inc
| #:null
| #:push
| #:append
| #:set-add
| #:set-add*
| #:pop
| #:shift
| #:pull
| #:pull*

struct : identifier?
collection : string?
field : identifier?

Defines make-struct and a set of operations for the fields.

Every field implicitly has the #:ref option. Every mutable field implicitly has the #:set! option. Every immutable field implicitly has the #:required option. It is an error for an immutable field to have any options other than #:required and #:ref, which are both implicit.

make-struct takes one keyword argument per field. If the field does not have the #:required option, the argument is optional and the instance will not contain a value for the field. make-struct returns a mongo-dict? .

If a field has the #:ref option, then struct-field is defined. It is implemented with mongo-dict-ref .

If a field has the #:set option, then set-struct-field! is defined. It is implemented with mongo-dict-set! .

If a field has the #:inc option, then inc-struct-field! is defined. It is implemented with mongo-dict-inc! .

If a field has the #:null option, then null-struct-field! is defined. It is implemented with mongo-dict-remove! .

If a field has the #:push option, then push-struct-field! is defined. It is implemented with mongo-dict-push! .

If a field has the #:append option, then append-struct-field! is defined. It is implemented with mongo-dict-append! .

If a field has the #:set-add option, then set-add-struct-field! is defined. It is implemented with mongo-dict-set-add! .

If a field has the #:set-add* option, then set-add*-struct-field! is defined. It is implemented with mongo-dict-set-add*! .

If a field has the #:pop option, then pop-struct-field! is defined. It is implemented with mongo-dict-pop! .

If a field has the #:shift option, then shift-struct-field! is defined. It is implemented with mongo-dict-shift! .

If a field has the #:pull option, then pull-struct-field! is defined. It is implemented with mongo-dict-pull! .

If a field has the #:pull* option, then pull*-struct-field! is defined. It is implemented with mongo-dict-pull*! .

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