You need to display the first names of all customers from the customers table that contain
the character ‘e’ and have the character ‘a’ in the second last position. Which query would
give the required output?
A.
Option A
B.
Option B
C.
Option C
D.
Option D
Explanation:
The SUBSTR(string, start position, number of characters) function accepts three parameters
and returns a string consisting of the number of characters extracted from the source string,
beginning at the specified start position:
substr(‘http://www.domain.com’, 12, 6) = domain
The position at which the first character of the returned string begins.
When position is 0 (zero), then it is treated as 1.
When position is positive, then the function counts from the beginning of string to find the
first character.
When position is negative, then the function counts backward from the end of string.
substring_length The length of the returned string. SUBSTR calculates lengths using
characters as defined by the input character set. SUBSTRB uses bytes instead of
characters. SUBSTRC uses Unicode complete characters.
SUBSTR2 uses UCS2 code points. SUBSTR4 uses UCS4 code points.
When you do not specify a value for this argument, then the function
The INSTR(source string, search item, [start position], [nth occurrence of search item])
function returns a number that represents the position in the source string, beginning from
the given start position, where the nth occurrence of the search item begins:
instr(‘http://www.domain.com’, ‘.’, 1, 2) = 18