PHP Manual: Handling of LONG columns

true odbc_longreadlen(Odbc\Result $statement, int $length)

Controls handling of LONG, LONGVARCHAR and LONGVARBINARY columns. The default length can be set using the uodbc.defaultlrl php.ini directive.

statement: The ODBC result object.
length: The number of bytes returned to PHP is controlled by the parameter length. If it is set to 0, long column data is passed through to the client (i.e. printed) when retrieved with odbc_result.

Always returns true.

Version	Description
8.4.0	`statement` expects an Odbc\Result instance now; previously, a resource was expected.

Note:
Handling of LONGVARBINARY columns is also affected by odbc_binmode.