SQL Where Comparison .

Using Comparison operators with WHERE statement.

• SQL provides a variety of operators and keywords for expressing the search condition, which include these:

• Comparison operators (=, <, >, and so on)

  Possible comparision operators:

  Operator	Meaning
  =	equal to
  >	greater than
  <	less than
  >=	greater than or equal to
  <=	less than or equal to
  <> or !=	not equal to

  Example:
  MySQL, Oracle, SQL server, PostgreSQL:

  select isbn_no "ISBN where order is over $100" ,
    ITEM_QTY * price "Order in $"
    from order_books
    where ITEM_QTY * price > 100 ;

  The result should be:

  ISBN where order is over $100	Order in $
  1861002025	190
  0764579088	140
  0201703092	390
  1861002025	190

• To select data from columns containing text use always text surrounded with '(single quotes) for the selection.
  Example:
  MySQL, Oracle, SQL server, PostgreSQL:

  select * from us_states  
     where US_STATE_CD>='CA'  and US_STATE_CD<='CZ'  

  The result should be:

  US_STATE_CD	US_STATE_NM
  CA	California
  CO	Colorado
  CT	Conneticut