How to select rows with a WHERE clause

      WHERE expression_1 operator expression_2
      

       =    Equal 
       >    Greater than
       <    Less than
       <=   Less than or equal to
       >=   Greater than or equal to
       <>   Not equal
      

      WHERE categoryID = 2
      

       WHERE productName = 'Gibson Les Paul'
      

      WHERE listPrice < 499.99
      

      WHERE listPrice >= 499.99
      

      WHERE productName < 'G'
      

      WHERE dateAdded < '2017-01-31'
      

      WHERE dateAdded >= '2017-01-31'
      

        discountPercent <> 30
      

Description

• If a comparison results in a TRUE value, the row being tested is included in the result set. If it’s FALSE or unknown, the row isn’t included.
• To use a string literal or a date literal in a comparison, enclose it in single quotes. To use a numeric literal, the single quotes are optional.
• Character comparisons are not case-sensitive.
• You can use a comparison operator to compare any two expressions that result in like data types. Although unlike data types may be converted to data types that can be compared, the comparison may produce unexpected results.