Data access is of primary concern to all programming languages, using either memory or disk. All files on disk can be considered a form of database. Reading and writing files is standard in all languages.
Once you start getting fancier in your files, and the data grows large, you need special ways to read it. A Postgres database can be considered a single big file on disk. It is the Postgres server that is required to access the file in the most efficient way to store and randomly access enormous amounts of general data.
SQLite is interesting in that there is no server, it's just a special library that enables efficient random access of a single file, which can be thought of as a black box that only SQLite knows how to interpret.
Unless you mean, making something like SQL built directly into the language as a first class citizen. Mumps did something like this https://en.wikipedia.org/wiki/MUMPS
Once you start getting fancier in your files, and the data grows large, you need special ways to read it. A Postgres database can be considered a single big file on disk. It is the Postgres server that is required to access the file in the most efficient way to store and randomly access enormous amounts of general data.
SQLite is interesting in that there is no server, it's just a special library that enables efficient random access of a single file, which can be thought of as a black box that only SQLite knows how to interpret.
Unless you mean, making something like SQL built directly into the language as a first class citizen. Mumps did something like this https://en.wikipedia.org/wiki/MUMPS