Some additional checks and documentation for new MAKE_DBKEY function.

doc/sql.extensions/README.builtin_functions.txt

@@ -693,6 +693,71 @@ Example:
     select lpad(x, 10) from y;
 
 
+----------
+MAKE_DBKEY
+----------
+
+Function:
+    MAKE_DBKEY( relation, recnum [, dpnum [, ppnum]] )
+    Creates DBKEY value using relation name or ID, record number, and, optionally,
+    logical number of data page and pointer page.
+
+Format:
+    MAKE_DBKEY( <value>, <number> [, <number> [, <number>]] )
+
+Notes:
+    1) If the first argument (relation) is a string expression or literal, then
+       it's treated as a relation name and the engine searches for the
+       corresponding relation ID. The search is case-sensitive.
+       In the case of string literal, relation ID is evaluated at prepare time. 
+       In the case of expression, relation ID is evaluated at execution time. 
+       If the relation couldn't be found, then isc_relnotdef error is raised.
+    2) If the first argument (relation) is a numeric expression or literal, then 
+       it's treated as a relation ID and used "as is", without verification
+       against existing relations.
+       If the argument value is negative or greater than the maximum allowed
+       relation ID (65535 currently), then NULL is returned.
+    3) Second argument (recnum) represents an absolute record number in relation 
+       (if the next arguments -- dpnum and ppnum -- are missing), or a record
+       number relative to the first record, specified by the next arguments.
+    4) Third argument (dpnum) is a logical number of data page in relation (if 
+       the next argument -- ppnum -- is missing), or number of data page
+       relative to the first data page addressed by the given ppnum.
+    5) Forth argument (ppnum) is a logical number of pointer page in relation.
+    6) All numbers are zero-based. 
+	   Maximum allowed value for dpnum and ppnum is 2^32 (4294967296).
+	   If dpnum is specified, then recnum could be negative.
+	   If dpnum is missing and recnum is negative then NULL is returned.
+	   If ppnum is specified, then dpnum could be negative.
+	   If ppnum is missing and dpnum is negative then NULL is returned.
+    7) If any of specified arguments has NULL value, the result is also NULL.
+	8) First argument (relation) is described as INTEGER but could be overriden
+	   by application as VARCHAR or CHAR.
+	   recnum, dpnum and ppnum are described as BIGINT (64-bit signed integer).
+
+Examples:
+
+	1) Select record using relation name (note, relation name is in uppercase)
+
+		select * from rdb$relations where rdb$db_key = make_dbkey('RDB$RELATIONS', 0)
+
+	2) Select record using relation ID
+
+		select * from rdb$relations where rdb$db_key = make_dbkey(6, 0)
+
+	3) Select all records that physically reside at first data page in relation
+
+		select * from rdb$relations
+		 where rdb$db_key >= make_dbkey(6, 0, 0)
+		   and rdb$db_key <  make_dbkey(6, 0, 1)
+
+	4) Select all records that physically reside at first data page of 6th pointer 
+	   page at relation
+
+		select * from SOMETABLE
+		 where rdb$db_key >= make_dbkey('SOMETABLE', 0, 0, 5)
+		   and rdb$db_key <  make_dbkey('SOMETABLE', 0, 1, 5)
+
 --------
 MAXVALUE
 --------

src/jrd/SysFunction.cpp

@@ -769,10 +769,10 @@ void setParamsMakeDbkey(DataTypeUtilBase*, const SysFunction*, int argsCount, ds
 		args[1]->makeInt64(0);
 
 	if (argsCount > 2 && args[2]->isUnknown())
-		args[2]->makeLong(0);
+		args[2]->makeInt64(0);
 
 	if (argsCount > 3 && args[3]->isUnknown())
-		args[3]->makeLong(0);
+		args[3]->makeInt64(0);
 }
 
 
@@ -847,14 +847,10 @@ void makeDbkeyResult(DataTypeUtilBase*, const SysFunction*, dsc* result,
 	int argsCount, const dsc** args)
 {
 	result->makeText(8, ttype_binary);
-
-	bool isNullable;
-	if (initResult(result, argsCount, args, &isNullable))
-		return;
-
-	result->setNullable(isNullable);
+	result->setNullable(true);
 }
 
+
 void makeDoubleResult(DataTypeUtilBase*, const SysFunction*, dsc* result,
 	int argsCount, const dsc** args)
 {
@@ -4862,7 +4858,7 @@ dsc* evlMakeDbkey(Jrd::thread_db* tdbb, const SysFunction* function, const NestV
 	else
 	{
 		const SLONG value = MOV_get_long(tdbb, argDsc, 0);
-		if (value > MAX_USHORT) // return NULL if the provided ID is too long
+		if (value < 0 || value > MAX_USHORT) // return NULL if the provided ID is too long
 			return NULL;
 
 		relId = (USHORT) value;
@@ -4874,7 +4870,7 @@ dsc* evlMakeDbkey(Jrd::thread_db* tdbb, const SysFunction* function, const NestV
 
 	SINT64 recNo = MOV_get_int64(tdbb, argDsc, 0);
 
-	ULONG dpNum = MAX_ULONG, ppNum = MAX_ULONG;
+	SINT64 dpNum = 0, ppNum = 0;
 
 	if (args.getCount() > 2)
 	{
@@ -4882,7 +4878,9 @@ dsc* evlMakeDbkey(Jrd::thread_db* tdbb, const SysFunction* function, const NestV
 		if (request->req_flags & req_null)
 			return NULL;
 
-		dpNum = MOV_get_long(tdbb, argDsc, 0);
+		dpNum = MOV_get_int64(tdbb, argDsc, 0);
+		if (dpNum > MAX_ULONG)
+			return NULL;
 	}
 
 	if (args.getCount() > 3)
@@ -4891,15 +4889,24 @@ dsc* evlMakeDbkey(Jrd::thread_db* tdbb, const SysFunction* function, const NestV
 		if (request->req_flags & req_null)
 			return NULL;
 
-		ppNum = MOV_get_long(tdbb, argDsc, 0);
+		ppNum = MOV_get_int64(tdbb, argDsc, 0);
+		if (ppNum < 0 || ppNum > MAX_ULONG)
+			return NULL;
 	}
 
 	RecordNumber temp;
 
 	if (args.getCount() == 4)
-		recNo += ((SINT64) ppNum * dbb->dbb_dp_per_pp + dpNum) * dbb->dbb_max_records;
+		recNo += (ppNum * dbb->dbb_dp_per_pp + dpNum) * dbb->dbb_max_records;
 	else if (args.getCount() == 3)
-		recNo += (SINT64) dpNum * dbb->dbb_max_records;
+	{
+		if (dpNum < 0)
+			return NULL;
+		recNo += dpNum * dbb->dbb_max_records;
+	}
+
+	if (recNo < 0)
+		return NULL;
 
 	temp.setValue(recNo + 1);