MySQL select column length in php

Question

Hello!

How do i get the actual max length of a specified column in php?

For instance, this table:

id - int(11) name - string(20)

I want in php to select the maximum number of characters that a field can have, like SELECT length(name) from table1

and it should then return 20 (since its the maximum number of characters for that field).

Answer 1

You should use mysql_field_len

http://php.net/manual/en/function.mysql-field-len.php

Answer 2

You can use mysql_field_len for a single column or use the SHOW COLUMNS FROM table query in MySQL to get information about all the columns at once.

Answer 3

Just be careful when using mysql_field_len to read columns that are not ints or strings. For example, decimal(6,4) will return 10 from mysql_field_len.

You may wish to use SHOW COLUMNS and parse the data, if you need all of the column information.