In the SQL:2003 standard, access to the data dictionary (or database metadata) is provided by a structure called
information_schema. As this is part of the standard, and already exists in other database systems, the decision to implement this feature into MySQL was a very good one.
MySQL has added some information that is not part of the standard—for example,
INFORMATION_SCHEMA.COLUMNS.COLUMN_TYPE. Beware of the fact that if you plan to use this information in a software project, it has to remain portable to other SQL implementations.
A phpMyAdmin user sees the
information_schema as a normal database containing views that describe many aspects of the structure of the databases hosted on this server. Here is a subset of what ...