• Antelope Release 5.10 Linux CentOS release 7.6.1810 (Core) 3.10.0 2020-05-12

 

NAME

dbquery - get ancillary information about a database

SYNOPSIS

#include "db.h"

int dbquery( Dbptr db, int code, void *value ) ;

DESCRIPTION

dbquery is the method for getting ancillary information (names, descriptions, number of rows, columns, tables, etc) about a database. Depending on the code, it may return an integer, a pointer to a character string, a pointer to a list (Tbl), or a pointer to an associative array (Arr).

Note that the returned information is often pointers to parts of Datascope's internal structures -- it should never be modified.

Please see the dbconstants(5) man page for an explanation of all the possible values for code.

RETURN VALUES

dbquery returns 0 or a positive integer for success. A negative value indicates some problem. A typical problem might be requesting a field value (like dbFIELD_NAME) when the input database pointer doesn't specify a field.

LIBRARY

$(DBLIBS)

DIAGNOSTICS

SEE ALSO

dbconstants(5)
dbintro(3)

BUGS AND CAVEATS

The value dbquery returns for the code dbNULL is the exact string from the schema; however, the string stored in a null record for that field can be different, for fields which are not String, because the schema value is first translated to the internal representation (eg, an integer) and then converted back to a string according to the specified Attribute format. The best way, therefore, to get the null value for a field is to use dbget(3) with the the null record.

AUTHOR

Daniel Quinlan
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