Mysql-database learning problems

Programmers, Cainiao, want to learn the database. the current level is limited to some basic SQL statements. then, they want to buy books to learn and check the recommended books, I found many books in the "MicrosoftSQLServer2005 Technology Insider" series and "SQLServer2005 development, management and application instances" recommended. I would like to ask, the content in these books is limited to the SQL server database or can be used to check whether there are any books that can be recommended. to learn the principles, it is better to directly learn SQL statements. mysqlsql serversql server 2005 database oracle

Programmers, Cainiao, want to learn the database. the current level is limited to some basic SQL statements, and then want to buy books to learn,
I checked the recommended books and found many of the series of "Microsoft SQL Server 2005 Technology Insider"
And SQL Server 2005 development, management, and application examples.
Only SQL server databases can be used.
In addition, check whether there are any books that can be recommended. it is more appropriate to directly learn the principles of SQL statements.