Name
ELT()
Synopsis
ELT(index
,string
, ...)
This function returns the index
element
from the list of strings given, where the list is numbered starting
with 1. If the number given is less than 1 or if the number of
elements is less than the number given, this statement returns
NULL:
SELECT student_id, CONCAT(name_first, SPACE(1), name_last) AS Name, ELT(primary_phone, phone_dorm, phone_home, phone_work) AS Telephone FROM students;
In this SQL statement, we’re using the value of the
primary_phone
column to provide the index for
ELT()
. This column is an
ENUM
column that records which of the three
telephone columns is the student’s primary telephone number. The
function will return the value for the column selected based on the
index. As a result, the SQL statement will give a list of students and
their primary telephone numbers.
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