I want to find max lenght of string from a tabe in SQLite

March 23, 2023

SELECT MAX(SELECT MAX(LENGTH(`name`)) count FROM `student_info` 
UNION SELECT MAX(LENGTH(`address`)) count FROM `student_info` 
UNION SELECT MAX(LENGTH(`class`)) count FROM `student_info` 
UNION SELECT MAX(LENGTH(`roll`)) count FROM `student_info` 
UNION SELECT MAX(LENGTH(`subject`)) count FROM `student_info`) 
FROM `student_info`

by using similar type of query i want to find one max value of string so i can manage table properly.

what is the proper query for SQLite?

>Solution :

Your query is mostly correct , just make minor change like below

SELECT MAX(count) from (
  SELECT MAX(LENGTH(`name`)) count FROM `student_info` 
UNION SELECT MAX(LENGTH(`address`)) count FROM `student_info` 
UNION SELECT MAX(LENGTH(`class`)) count FROM `student_info` 
UNION SELECT MAX(LENGTH(`roll`)) count FROM `student_info` 
UNION SELECT MAX(LENGTH(`subject`)) count FROM `student_info`
) ;

Try Here