User's Guide

Part II. Tutorials

Chapter 7. Selecting Data from Database Tables

Another useful way to look for things is to search for a pattern. In SQL, the word LIKE is used to search for patterns. The use of LIKE can be explained by example.

To list all employees whose last name begins with BR:

• Type the following:

       SELECT emp_lname, emp_fname
       FROM employee
       WHERE emp_lname LIKE 'br%'
  

emp_lname	emp_fname
Breault	Robert
Braun	Jane

The % in the search condition indicates that any number of other characters may follow the letters BR.

To list all employees whose surname begins with BR, followed by zero or more letters and a T, followed by zero or more letters:

• Type the following:

       SELECT emp_lname, emp_fname
       FROM employee
       WHERE emp_lna -me LIKE 'BR%T%'
  

emp_lname	emp_fname
Breault	Robert

The first % sign matches the string eaul , while the second % sign matches the empty string (no characters).

Another special character that can be used with LIKE is the _ (underscore) character, which matches exactly one character.

The pattern BR_U% matches all names starting with BR and having U as the fourth letter. In Braun the _ matches the letter A and the % matches N.