Oracle SQL Developer

Entering and Executing PL/SQL CodeYou can nest blocks in the executable and exception-handling parts of a PL/SQL blockor subprogram, but not in the declarative part. You can define local subprograms inthe declarative part of any block. You can call local subprograms only from the blockin which they are defined.■■■Anonymous blockAn anonymous block is a PL/SQL block that appears in your application and isnot named or stored in the database. In many applications, PL/SQL blocks canappear wherever SQL statements can appear. A PL/SQL block groups relateddeclarations and statements.Stored or standalone subprogramA stored or standalone subprogram is a PL/SQL block that Oracle stores in thedatabase and can be called by name from an application. Subprograms can beprocedures or functions; the difference is that functions return a value whenexecuted. When you create a stored subprogram, Oracle parses the subprogramand stores its parsed representation in the database. See Subprograms andPackages: Usage Information.PackageA package is a group of subprograms and variable definitions that Oracle stores inthe database. Subprograms and variables in packages can be called from otherpackages or subprograms. See Subprograms and Packages: Usage Information.7.2 Entering and Executing PL/SQL CodePL/SQL code can be entered and executed from the SQL Workshop or the SQL*Pluscommand line.In the SQL Workshop, you can save your SQL statements as a script file that can be runas a SQL script with SQL*Plus.If you use SQL*Plus, simply type in each line of code at the SQL prompt. Forinformation on using SQL*Plus, see SQL*Plus: Usage Information.You can create a text file of the PL/SQL code and run that as a SQL script. Using ascript makes correcting mistakes much easier because you only need to make thenecessary updates to correct the problem rather than retyping all the PL/SQL code.For information on running SQL scripts from SQL*Plus, see Running Scripts FromSQL*Plus.7.3 Utilizing the Main Features of PL/SQLPL/SQL combines the data-manipulating power of SQL with the processing power ofprocedural languages. You can control program flow with statements like IF andLOOP. As with other procedural programming languages, you can declare variables,define procedures and functions, and trap runtime errors.PL/SQL lets you break complex problems down into easily understandableprocedural code, and reuse this code across multiple applications. When a problemcan be solved through plain SQL, you can issue SQL commands directly inside yourPL/SQL programs, without learning new APIs. PL/SQL data types correspond withSQL column types, making it easy to interchange PL/SQL variables with data inside atable.■■Using PL/SQL Block StructureUsing Comments7-2 SQL Developer Online Help