Oracle Database 10g Express Edition PHP Web Programming

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.

The first dimension of the array is a list of values indexed by column names from one or more tables. The elements in the list of ...