Determine whether the specified regular result column’s data can vary in length.
DBBOOL dbvarylen(dbproc, column) DBPROCESS *dbproc; 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 number of the regular result column of interest. The first column is number 1.
“TRUE” or “FALSE”, indicating whether or not the column’s data can vary in length. dbvarylen also returns “FALSE” if the column number is out of range.
This routine indicates whether a particular regular (that is, non-compute) result column’s data can vary in length. It will return “TRUE” if the result column is derived from a database column of type varchar, varbinary, text, image, boundary, or sensitivity. It will also return “TRUE” if the source database column is defined as NULL, meaning that it may contain a null value.
This routine is useful with programs that handle ad hoc queries, if the program needs to be alerted to the possibility of null or variable length data.
You can use dbcoltype to determine a column’s datatype. See Types for a list of datatypes.
dbcollen, dbcolname, dbcoltype, dbdata, dbdatlen, dbnumcols, dbprtype
