Add date and time datatype handling to convert_to_scalar. (I was waiting

for Thomas to do the datetime consolidation before touching this, but
it's done now...)

diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index 6b1f5cde26f1ec44f238985e6825a1d0e4ec2476..ff5ec332ea2fa950e6aee86970368b321f2eb789 100644 (file)
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -15,7 +15,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/utils/adt/selfuncs.c,v 1.56 2000/02/16 00:59:27 tgl Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/utils/adt/selfuncs.c,v 1.57 2000/02/26 23:03:12 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -470,9 +470,19 @@ scalargtjoinsel(Oid opid,
  *   Returns "true" if successful.
  *
  * All numeric datatypes are simply converted to their equivalent
- * "double" values.  String datatypes are converted to a crude scale
- * using their first character (only if it is in the ASCII range,
- * to try to avoid problems with non-ASCII collating sequences).
+ * "double" values.
+ *
+ * String datatypes are converted to a crude scale using their first character
+ * (only if it is in the ASCII range, to try to avoid problems with non-ASCII
+ * collating sequences).
+ *
+ * The several datatypes representing absolute times are all converted
+ * to Timestamp, which is actually a double, and then we just use that
+ * double value.  Note this will give bad results for the various "special"
+ * values of Timestamp --- what can we do with those?
+ *
+ * The several datatypes representing relative times (intervals) are all
+ * converted to measurements expressed in seconds.
  */
 bool
 convert_to_scalar(Datum value, Oid typid,
@@ -551,12 +561,63 @@ convert_to_scalar(Datum value, Oid typid,
            break;
        }
 
+       /*
+        * Built-in absolute-time types
+        */
+       case TIMESTAMPOID:
+           *scaleval = * ((Timestamp *) DatumGetPointer(value));
+           return true;
+       case ABSTIMEOID:
+           *scaleval = * abstime_timestamp(value);
+           return true;
+       case DATEOID:
+           *scaleval = * date_timestamp(value);
+           return true;
+
+       /*
+        * Built-in relative-time types
+        */
+       case INTERVALOID:
+       {
+           Interval   *interval = (Interval *) DatumGetPointer(value);
+
+           /*
+            * Convert the month part of Interval to days using assumed
+            * average month length of 365.25/12.0 days.  Not too accurate,
+            * but plenty good enough for our purposes.
+            */
+           *scaleval = interval->time +
+               interval->month * (365.25/12.0 * 24.0 * 60.0 * 60.0);
+           return true;
+       }
+       case RELTIMEOID:
+           *scaleval = (RelativeTime) DatumGetInt32(value);
+           return true;
+       case TINTERVALOID:
+       {
+           TimeInterval    interval = (TimeInterval) DatumGetPointer(value);
+
+           if (interval->status != 0)
+           {
+               *scaleval = interval->data[1] - interval->data[0];
+               return true;
+           }
+           break;
+       }
+       case TIMEOID:
+           *scaleval = * ((TimeADT *) DatumGetPointer(value));
+           return true;
+
        default:
        {
            /*
             * See whether there is a registered type-conversion function,
             * namely a procedure named "float8" with the right signature.
             * If so, assume we can convert the value to the numeric scale.
+            *
+            * NOTE: there are no such procedures in the standard distribution,
+            * except with argument types that we already dealt with above.
+            * This code is just here as an escape for user-defined types.
             */
            Oid         oid_array[FUNC_MAX_ARGS];
            HeapTuple   ftup;