KEY
---
Curly braces group alternatives together, 
  and alternatives are separated by pipes:  {this | that | t'other}
Clauses in brackets are optional:            You [and john] can come.
An asterisk indicates 0 or more instances:   I like to eat[ and eat]*.
A plus-sign indicates 1 or more instances:   Run fast,[ go]+!
A plus-sign also indicates addition:         select (1 + 3) from dual;

Elements are defined in terms of other elements.  
  <number> : [0-9]+  means that a number is composed of one or more digits.
  <datatype>: {integer | char(<number>) | varchar2(<number>) | date}
means that a <datatype> element is one of the four strings shown.
  <column-set>: <column> = <expression>
means that a <column-set> element is composed of a <column>, followed by
an equals sign and an <expression>.

Readability of PL/SQL is much improved by highlighting certain keywords;
this is why some word are in all caps.
---


INSERTS and UPDATES
-------------------
<insert>: insert into <tablename> [<columns>] {values <values> | <select>} 
<select>: select [distinct] <columns> from <tables> [<where>] [group-by]
<select-union>:  <select> union <select> [<order-by>]
<select-order>:  <select> <order-by>

<update>    : update <tablename> set <column-set> [, <column-set>] [<where>]
<column-set>: <column> = <expression>
<update-from-query>: update <tablename> set <columns> = <select> [<where>]


FUNDAMENTALS
------------
<name>    : [a-zA-Z][a-zA-Z0-9_]*   - that is, a string of alphanumeric chars
                                   and underscores starting with an alpha char.
<number>  : [0-9]+
<datatype>: {integer | char(<number>) | varchar2(<number>) | date}

<ora-alias>: a temporary nickname for a table or column, for the purposes
             of condensing a query.

LITERALS
--------
<value>      : {<number> | <string> | <number-expr> | <string-expr>}
<values>     : ( <value> [, <value>]* )
<number-expr>: {<number> | <column-name>} +  [<number> | <column-name>]*
<string-expr>: {<string> | <column-name>} || [<string> | <column-name>]*


NAMES and DEFINITIONS
---------------------
<column-name>: name of a column in a table in the current scope
<columns>    : ( <column-name> <ora-alias> [, <column-name> <ora-alias>]* )
<new-column> : <name> <column-def>
<new-columns>: <new-column> [, <new-column>]*
<column-def> : <datatype> [default <value>] [<constraint>]*

<table-name> : name of a table in the current scope
<tables>     : <table-name> <ora-alias> [, <table-name> <ora-alias>]* 

<constraint> : {not null | primary key | references <table-name>}


CREATION
--------
<create-table-new> : create table <name> ( <new-columns> )
<create-table-from>: create table <name> as <select>

<create-tablespace>: create tablespace <name> datafile '<filespec>'
           size 50m autoextend on default storage (pctincrease 1);
<filespec>         :  /opt/ora8/m02/oradata/ora8/<name>01.dbf

<create-user> : create user <name> identified by <db-password> 
       default tablespace <name> temporary tablespace temp quota 
       unlimited on <name>;
<grant-user>  : grant connect, resource, ctxapp to <name>;
                grant javasyspriv to <name>;


ADDING, DROPPING, AND DELETION
------------------------------
<add-column> : alter table <table-name> add ( <new-columns> )
<drop-column>: alter table <table-name> drop column <column-name>

<drop>  : drop {table|view|sequence|function} <name> 
<delete>: delete from <table-name> [<where>]



PL-SQL BASICS
-------------
<var-name> : A variable passed into a function, or definied in <declarations>
<argument> : <name> IN <datatype>
<arguments>: <argument> [, <argument>]*
<args>     :    <value> [, <value>]*


PL-SQL
------
<create-function>: create or replace function <name> ( <arguments> )
            return <datatype> AS [<declarations>] BEGIN <function-body> END;

<declarations> : <name> <datatype>[:= <value>];
<function-body>: [{<statement> | <loop>};]*  
                    return {<var-name> | <value>};

<statement>: { <var-name> := {<expression> | <function>} |  
               open cursor <cursor-name>                 |
               fetch <cursor-name> into <var-name>}      |
               
<loop>     : LOOP [{<statement> | <loop>};]*
               exit when <condition>
             END LOOP; 

<ora-call-function>: select <name>(<args>) from dual;