Oracle SQL & PL/SQL

Wild Charcters :- These characters are used to provide pattern matching which means comparision to data is provided with partial value. ORACLE provides the following wild characters.            i)      _(Underscore) -> Represents single character.             ii)      %(Percentage) -> Represents group of character. Ø   Inorder to have wild characters for the comparision to partial data, LIKE operator is used. Ø   If these wild characters are formed in data, then the wild characters can be converted to data using ‘\’ (backslash). It is represented through an option called ‘ESCAPE’ , which is written after like operator. Examples :- Display employee number and employee name of all those employees whose names contain 4 characters. Ans : select empno, ename from emp           Where ename LIKE ‘---...