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Example of Sequences in SQL:

Assume we have executed the following create table statement.

create table employees (

  eno     number(4) primary key,

  ename   varchar(30),

  zip     number(5),

  hdate   date);  

Now we create a sequence object.

  create sequence EnumberSeq start with 1000;

Now execute the following insert statements:

  insert into employees values

   (EnumberSeq.nextval, 'Tom Jones', 67226,'12-DEC-00');

Jones will be assigned a value of 1000 for column eno.

  insert into employees values

   (EnumberSeq.nextval, 'Ruth Brown',67226,'12-DEC-00');

Brown will be assigned a value of 1001 for column eno.

 

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Example of Dates in SQL:

Default format is 'DD-MON-YY"  

  where DD is 2 digit day of month

        MON is 3 letter abbreviation for month

        YY is last 2 digits of year

Other formats include

        MM   2 digit month

        DY   3 letter abbreviation for day 

      YYYY   4 digit year 

Finding the current date:

   Select sysdate from dual;    dual is a system defined dummy table with one column and one row.

The to_char function allows us to reformat a date 

 

    Select to_char(sysdate, 'DD-MON')

    from dual;

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Execute a file containing SQL statements:

   Create a file, for example, mysqlfile.sql (using your favorite editor) of SQL statements,
   remember to terminate each statement with a semicolon

   logon to Oracle and issue the following command at the sqlplus prompt with your file name:
   sqlplus> start mysqlfile

   this will execute every SQL statement in your file mysqlfile.sql
 

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