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This pocket reference provides quickreference information that will help you use Oracle Corporation`s extensive set of builtin functions and packages, including those new to Oracle8. Oracle`s PL/SQL language is a programming language providing procedural extensions to the SQL relational database language and to an evergrowing number of Oracle development tools. Among the most useful constructs in the PL/SQL language are the builtin functions and packages. Builtin functions are constructs that operate on certain types of data (e.g., numeric, character) to return a result. By using functions, you can minimize the coding you need to do in your programs. Functions are described in detail in Steven Feuerstein`s Oracle PL/SQL Programming; this comprehensive guide to building applications with PL/SQL has become the bible for PL/SQL developers who have raved about its completeness, readability, and practicality. Builtin functions fall into several major categories: Character functions: Operate on character data. Examples include CONCAT (concatenates two strings into one), LENGTH (returns the length of a string), and REPLACE (replaces a character sequence in a string with a different set of characters). Date functions: Operate on dates and supplement the DATE datatype. Examples include SYSDATE (returns the current date and time in the Oracle Server) and LAST_DAY (returns the last day in the month of the specified date). Numeric functions: Operate on numeric data. Examples include CEIL (returns the smallest integer greater than or equal to the specified number) and POWER (returns a number raised to a particular power). LOB functions: Operate on large object data. Examples include EMPTY_BLOB (returns an empty locator of the binary large object type) and EMPTY_CLOB (returns an empty locator of the character large object type). Conversion functions: Perform explicit conversions of different types of data. Examples include TO_CHAR (converts a number or date to a string) and TO_NUMBER (converts a string to a number). Miscellaneous functions. Examples include GREATEST (returns the greatest of the specified list of values) and UID (returns the user ID of the current Oracle session). Builtin packages (collections of PL/SQL objects, such as functions, procedures, and data structures) greatly expand the scope of the PL/SQL language. These packages are described in detail in Feuerstein`s and Beresniewicz`s book, Oracle Builtin Packages. Builtin packages are built by Oracle Corporation and stored directly in the Oracle database. The functionality of the builtins is available from any programming environment that can call PL/SQL stored procedures, including Visual Basic, Oracle Developer/2000, Oracle Application Server (for Webbased development), and, of course, the Oracle database itself. Builtin packages extend the capabilities and power of PL/SQL in many significant ways. For example: DBMS_SQL executes dynamically constructed SQL statements and PL/SQL blocks of code. DBMS_PIPE communicates between different Oracle sessions through a pipe in the RDBMS shared memory. DBMS_JOB submits and manages regularly scheduled jobs for execution inside the database. DBMS_LOB accesses and manipulates Oracle8`s large objects (LOBs) from within PL/SQL programs. The book shows how to call all of the commonly used builtin functions and packages. For packages, it also shows the RESTRICT REFERENCES pragmas (needed if you call packages from a SQL statement), as well as the exceptions, constants, and data structures defined in the packages.
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