# GraphQL Relational Modeling Transformers # Reference Documentation ### @hasOne The `@hasOne` directive allows you to define "has one" relationships between data. #### Definition ```graphql directive @hasOne(fields: [String!]) on FIELD_DEFINITION ``` ### @hasMany The `@hasMany` directive allows you to define "has many" relationships between data. #### Definition ```graphql directive @hasMany(indexName: String, fields: [String!], limit: Int = 100) on FIELD_DEFINITION ``` ### @belongsTo The `@belongsTo` directive allows you to define "belongs to" relationships between data. #### Definition ```graphql directive @belongsTo(fields: [String!]) on FIELD_DEFINITION ``` ### @manyToMany The `@manyToMany` directive allows you to define "many to many" relationships between data. #### Definition ```graphql directive @manyToMany(relationName: String!, limit: Int = 100) on FIELD_DEFINITION ```