I found the following useful - just a way of using PQgetisnull from

bmomjian · bmomjian · commit 4b06f6f9c84a · 1999-09-21T21:19:31.000Z
libpq++.

Patrick Welche
diff --git a/src/interfaces/libpq++/pgdatabase.cc b/src/interfaces/libpq++/pgdatabase.cc
@@ -10,7 +10,7 @@
  * Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/interfaces/libpq++/Attic/pgdatabase.cc,v 1.3 1999/06/05 18:05:17 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/interfaces/libpq++/Attic/pgdatabase.cc,v 1.4 1999/09/21 21:19:31 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -115,6 +115,18 @@ return PQgetvalue(pgResult, tup_num, FieldNum(field_name));
 }
 
 
+int PgDatabase::GetIsNull(int tup_num, int field_num)
+{ 
+return PQgetisnull(pgResult, tup_num, field_num); 
+}
+
+
+int PgDatabase::GetIsNull(int tup_num, const char* field_name)
+{ 
+return PQgetisnull(pgResult, tup_num, FieldNum(field_name)); 
+}
+
+
 int PgDatabase::GetLength(int tup_num, int field_num)
 { 
 return PQgetlength(pgResult, tup_num, field_num); 
@@ -126,6 +138,7 @@ int PgDatabase::GetLength(int tup_num, const char* field_name)
 return PQgetlength(pgResult, tup_num, FieldNum(field_name)); 
 }
 
+
 int PgDatabase::GetLine(char* string, int length)
 { 
 return PQgetline(pgConn, string, length); 
diff --git a/src/interfaces/libpq++/pgdatabase.h b/src/interfaces/libpq++/pgdatabase.h
@@ -13,7 +13,7 @@
  * Copyright (c) 1994, Regents of the University of California
  *
  *
- *  $Id: pgdatabase.h,v 1.2 1999/05/23 01:04:01 momjian Exp $
+ *  $Id: pgdatabase.h,v 1.3 1999/09/21 21:19:31 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -48,6 +48,8 @@ class PgDatabase : public PgConnection {
   short FieldSize(const char* field_name);
   const char* GetValue(int tup_num, int field_num);
   const char* GetValue(int tup_num, const char* field_name);
+  int GetIsNull(int tup_num, int field_num);
+  int GetIsNull(int tup_num, const char* field_name);
   int GetLength(int tup_num, int field_num);
   int GetLength(int tup_num, const char* field_name);
   void DisplayTuples(FILE *out = 0, int fillAlign = 1, 

Original file line number	Diff line number	Diff line change
`@@ -10,7 +10,7 @@`
`10`	`10`	`* Copyright (c) 1994, Regents of the University of California`
`11`	`11`	`*`
`12`	`12`	`* IDENTIFICATION`
`13`		`- * $Header: /cvsroot/pgsql/src/interfaces/libpq++/Attic/pgdatabase.cc,v 1.3 1999/06/05 18:05:17 tgl Exp $`
	`13`	`+ * $Header: /cvsroot/pgsql/src/interfaces/libpq++/Attic/pgdatabase.cc,v 1.4 1999/09/21 21:19:31 momjian Exp $`
`14`	`14`	`*`
`15`	`15`	`*-------------------------------------------------------------------------`
`16`	`16`	`*/`
`@@ -115,6 +115,18 @@ return PQgetvalue(pgResult, tup_num, FieldNum(field_name));`
`115`	`115`	`}`
`116`	`116`
`117`	`117`
	`118`	`+int PgDatabase::GetIsNull(int tup_num, int field_num)`
	`119`	`+{`
	`120`	`+return PQgetisnull(pgResult, tup_num, field_num);`
	`121`	`+}`
	`122`	`+`
	`123`	`+`
	`124`	`+int PgDatabase::GetIsNull(int tup_num, const char* field_name)`
	`125`	`+{`
	`126`	`+return PQgetisnull(pgResult, tup_num, FieldNum(field_name));`
	`127`	`+}`
	`128`	`+`
	`129`	`+`
`118`	`130`	`int PgDatabase::GetLength(int tup_num, int field_num)`
`119`	`131`	`{`
`120`	`132`	`return PQgetlength(pgResult, tup_num, field_num);`
`@@ -126,6 +138,7 @@ int PgDatabase::GetLength(int tup_num, const char* field_name)`
`126`	`138`	`return PQgetlength(pgResult, tup_num, FieldNum(field_name));`
`127`	`139`	`}`
`128`	`140`
	`141`	`+`
`129`	`142`	`int PgDatabase::GetLine(char* string, int length)`
`130`	`143`	`{`
`131`	`144`	`return PQgetline(pgConn, string, length);`
Original file line number	Diff line number	Diff line change
`@@ -13,7 +13,7 @@`
`13`	`13`	`* Copyright (c) 1994, Regents of the University of California`
`14`	`14`	`*`
`15`	`15`	`*`
`16`		`- * $Id: pgdatabase.h,v 1.2 1999/05/23 01:04:01 momjian Exp $`
	`16`	`+ * $Id: pgdatabase.h,v 1.3 1999/09/21 21:19:31 momjian Exp $`
`17`	`17`	`*`
`18`	`18`	`*-------------------------------------------------------------------------`
`19`	`19`	`*/`
`@@ -48,6 +48,8 @@ class PgDatabase : public PgConnection {`
`48`	`48`	`short FieldSize(const char* field_name);`
`49`	`49`	`const char* GetValue(int tup_num, int field_num);`
`50`	`50`	`const char* GetValue(int tup_num, const char* field_name);`
	`51`	`+ int GetIsNull(int tup_num, int field_num);`
	`52`	`+ int GetIsNull(int tup_num, const char* field_name);`
`51`	`53`	`int GetLength(int tup_num, int field_num);`
`52`	`54`	`int GetLength(int tup_num, const char* field_name);`
`53`	`55`	`void DisplayTuples(FILE *out = 0, int fillAlign = 1,`