Selection Queries

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      These guides explain how to read data with a SQL++ query. The SQL++ query language enables you to retrieve a document by inspecting its contents to see if it matches a certain criterion. Key-value operations are quicker, but querying documents allows for richer search capabilities — for example, "Give me all likes and followed users located in the US", versus "Give me a user with the ID e3d882a4".

      This page is for Couchbase Server.

      Selecting Data with Queries

      To read data from a data source using SQL++, you must use a selection query; that is, a query using the SELECT statement.

      Querying Across Relationships

      You can use a join to read objects from one data source, combine them with corresponding objects from another data source, and return the joined objects.

      Nesting and Unnesting Documents

      SQL++ provides syntax which enables you to nest (create) or unnest (flatten) arrays of embedded documents in a query.

      Grouping and Aggregation

      You can use aggregate functions to perform calculations over multiple values. Grouping enables you to display the results in groups.