Unlike relational databases, document databases like CouchDB and MongoDB do not directly support entity relationships. This talk will explore patterns of modeling one-to-many and many-to-many entity relationships in a document database. These patterns include using an embedded JSON array, relating documents using identifiers, using a list of keys, and using relationship documents. This talk will explore how these entity relationship patterns equate to how entities are joined in a relational database. We'll take a look at the relevant differences between document databases and relational databases. For example, document databases do not have tables, each document can have its own schema, there is no built-in concept of relationships between documents, views/indexes are queried directly instead of being used to optimize more generalized queries, a column within a result set can contain a mix of logical data types, and there is typically no support for transactions across document boundaries.