Returns the maximum length of the data for a compute column.
DBINT dbaltlen (
INT column );
The DBPROCESS structure that is the handle for a particular workstation or Microsoft® SQL Server™ 2000 process. It contains all the information that DB-Library uses to manage communications and data between the workstation and SQL Server.
The ID that identifies the COMPUTE clause. A SELECT statement can have multiple COMPUTE clauses, which can have varying numbers of aggregate operators and aggregate targets. The computeid is returned by dbnextrow or dbgetrow.
The number of the column. The first column is number 1.
The maximum number of bytes that the data can be for a particular column in a compute. When no such column or compute exists, -1 is returned.
dbaltlen returns the maximum length, in bytes, for a particular column in a compute row. For variable-length data, this is not necessarily the actual length of the data, but rather the maximum length. Calling dbaltlen only after dbnextrow or dbgetrow returns a computeid. For the actual data length, use dbadlen.
After the following SELECT statement, calling dbaltlen(dbproc, 1, 1) returns 4, because counts are of SQLINT4 type, which is 4 bytes long:
SELECT dept, name FROM employee ORDER BY dept, name COMPUTE COUNT(name) BY dept