MySQL Connector/C++ is a library for applications written in C or C++ that communicate with MySQL database servers. Version 9 of Connector/C++ implements three different APIs which can be used by applications:

The X DevAPI for applications written in C++.
The X DevAPI for C for applications written in plain C.
The classic JDBC4-based API that was also implemented in earlier versions of the connector.

X DevAPI and X DevAPI for C give access to MySQL implementing a document store. Internally these APIs use the X Protocol to communicate with the MySQL Server. Consequently, code written against these APIs can work only with MySQL Server 8 or later. Apart from accessing the document store, these APIs allow executing traditional SQL queries as well. The classic JDBC4-based API, on the other hand, uses the classic protocol and can communicate with older versions of the MySQL Server. It can work only with SQL queries and does not support CRUD operations over the document store. The API to be used is chosen by including appropriate set of headers, as explained in Using Connector/C++.

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