Free Trial

Safari Books Online is a digital library providing on-demand subscription access to thousands of learning resources.

  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint
Share this Page URL
Help

Part V: Appendixes > Data Query Language (DQL)

Data Query Language (DQL)

DQL commands are basically SELECT statements. SELECT statements let you query the database to find information in one or more tables, and return the query as a result set. A result set is an array structure, or more precisely in computerese, a result set is a two-dimensional array. You can find a discussion of two-dimensional arrays in Chapter 6.

Note

A SELECT statement with a FOR UPDATE clause is a transaction and DML statement, not a DQL query. This is a fine distinction, but critical should you encounter an ORA-22292 error while working with the DBMS_LOB package covered in Chapter 15.



  

You are currently reading a PREVIEW of this book.

                                                                                                                    

Get instant access to over $1 million worth of books and videos.

  

Start a Free Trial


  
  • Safari Books Online
  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint