Oracle Database/Regular Expression Support

REGEXP_LIKE
REGEXP_LIKE performs complex regular expression pattern matching and supports much greater range of string patterns than LIKE. this function is introduced in 10g.

last name begin with T and the 2nd character is either 'o' or 'u'

last name begin with 'T' and end with 'r'

first name is either 'Steven' or 'Stephen'

last name contain double vowel characters (ie. 'aa', 'ee', 'ii', 'oo', 'uu') and the matching is non-case sensitive

REGEXP_INSTR
REGEXP_INSTR performs complex regular expression pattern matching and supports much greater range of string patterns than INSTR. this function is introduced in 10g.

show the position of the 1st lowercase vowel characters

REGEXP_SUBSTR
REGEXP_SUBSTR performs complex regular expression pattern matching and supports much greater range of string patterns than SUBSTR. this function is introduced in 10g.

extract the 1st character if the last name start with 'A' or 'C'

Start at 3rd position, extract 2 characters from the last name

REGEXP_COUNT
REGEXP_COUNT performs count against a value and it is different from the aggregate COUNT function. This function is introduced in 11g.

find the occurrences of the vowel pattern in the last name