Protect special characters

The following query uses the keyword ESCAPE with LIKE or MATCHES so you can protect a special character from misinterpretation as a wildcard symbol.

Figure 1. Query

SELECT * FROM cust_calls
   WHERE res_descr LIKE '%!%%' ESCAPE '!';

The ESCAPE keyword designates an escape character (! in this example) that protects the next character so that it is interpreted as data and not as a wildcard. In the example, the escape character causes the middle percent sign (%) to be treated as data. By using the ESCAPE keyword, you can search for occurrences of a percent sign (%) in the res_descr column by using the LIKE wildcard percent sign (%). The query retrieves the following row.

Figure 2. Query result

customer_num   116
call_dtime     1997-12-21 11:24
user_id        mannyn
call_code      I
call_descr     Second complaint from this customer! 
               Received two cases righthanded outfielder 
               glove (1 HRO) instead of one case lefties.
res_dtime      1997-12-27 08:19
res_descr      Memo to shipping (Ava Brown) to send case 
               of lefthanded gloves, pick up wrong case;
               memo to billing requesting 5% discount to 
               placate customer due to second offense 
               and lateness of resolution because of
               holiday.