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Principal Features…
ANSI compliant SQL support
PL/SQL procedural language
- Procedures, functions, triggers
- Procedural language
- Conditional logic
- Variable definition, etc
SQL*Plus, iSQL*Plus
- Utility for ad-hoc query, PL/SQL development, database administration
Notes:
As with most relational database vendors, Oracle supports ANSI standard SQL, but adds its’ own proprietary extensions. Even the standard SQL SELECT statement has its’ extensions. For example, Oracle provides CONNECT BY for reporting-type queries against hierarchical data and the NOWAIT option to avoid waiting for exclusive lock access.
An important extension is PL/SQL, formally called Procedural Language Extensions to SQL. It is a 4th generation language that we use to write database procedures, functions and triggers. (Note that Oracle8i and up also supports Java for this purpose.) As a 4GL, it provides conditional logic (e.g. IF statement), variable definition and assignment, looping and branching constructs.
One of the standard tools that is provided with Oracle is SQL*Plus. It is used for ad-hoc query, database administration and PL/SQL development. SQL*Plus is often called the “query tool”, though is supports all SQL statements. It is a ubiquitous “free” utility (shipped with all editions and releases of the Oracle database), and thus is required learning. Its use is covered in detail in the SkillBuilders Introduction to Oracle for Developers course. iSQL*Plus is a new browser-based version of SQL*Plus, introduced with Oracle9i.