Find the length of the longest row in a column in oracle

Question

Does anybody know if there is a way to find what the length of the longest row in a column in Oracle?

Basically I need to get the length of the longest row and then use that length plus 1 with SUBSTR to make the output of the column one character longer than the longest string.

Thanks

EDIT:

Thanks for the advice.

However, the MAX(LENGTH(column_name)) AS MAXLENGTH approach gives me the number I want but when I try to use it with SUBSTR(column_name,1, MAXLENGTH) I get an invalid identifier error.

SO I made a function to return the numberI wanted then used:

SUBSTR(column_name,1,maxlengthfunc)

This gave me the following output:

SUBSTR(NAME,1,MAXLENGTHFUNC)

Rather than:

SUBSTR(NAME, 1, 19)

And it didn't shrink the output column size like I needed.

Also

RTRIM(name)||' '

didn't do anything for me in SQL developer.

Thanks.

Solution 1

This will work with VARCHAR2 columns.

select max(length(your_col))
from your_table
/

CHAR columns are obviously all the same length. If the column is a CLOB you will need to use DBMS_LOB.GETLENGTH(). If it's a LONG it's really tricky.

Solution 2

SELECT max(length(col_name)+1) as MyOutput
FROM table_Name

Normal output would look like

   MyOutput
1     5

New output would look like

   MyOutput
1     6

Solution 3

select max(length(MyColumn)) as MaxLength
from MyTable

Solution 4

select max(LENGTH(column_name)) from table_name.

Solution 5

This should do what you want:

select max(length(MyColumn)) from MyTable;

Depending on what you are trying to achieve, you may also be insterested to know that you can output the data in the column plus exactly one space like this:

select rtrim(MyColumn)||' ' from MyTable;

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