Return the maximum length of the data for a particular compute column.
DBINT dbaltlen(dbproc, computeid, column) DBPROCESS *dbproc; int computeid; int column;
A pointer to the DBPROCESS structure that provides the connection for a particular front-end/server process. It contains all the information that DB-Library uses to manage communications and data between the front end and server.
The ID that identifies the particular compute row of interest. A SQL select statement may have multiple compute clauses, each of which returns a separate compute row. The computeid corresponding to the first compute clause in a select is 1. The computeid is returned by dbnextrow or dbgetrow.
The number of the column of interest. The first column is number 1.
The maximum length, in bytes, possible for the data in a particular compute column. dbaltlen returns -1 if there is no such column or compute clause.
This routine returns the maximum length for a column in a compute row. In the case of variable length data, this is not necessarily the actual length of the data, but rather the maximum length. For the actual data length, use dbadlen.
For example, given the SQL statement:
select dept, name from employee
order by dept, name
compute count(name) by dept
the call dbaltlen(dbproc, 1, 1) returns 4 because counts are of SYBINT4 type, which is 4 bytes long.
