The driver models the data in Gmail into a list of tables that can be queried using standard SQL statements.

Generally, querying Gmail tables is the same as querying a table in a relational database. Sometimes there are special cases, for example, including a certain column in the WHERE clause might be required to get data for certain columns in the table. This is typically needed for situations where a separate request must be made for each row to get certain columns. These types of situations are clearly documented at the top of the table page linked below.

CData JDBC Driver for Gmail Tables