Some stuff I had on another machine and which might provide useful.

pgsql/Pgsql_PgException.cpp

@@ -0,0 +1 @@
+#include "Pgsql_PgException.h"

pgsql/Pgsql_PgException.h

@@ -0,0 +1,94 @@
+#ifndef PGEXCEPTION_H
+#define PGEXCEPTION_H
+
+#include <stdexcept>
+#include <utility>
+
+namespace Pgsql {
+
+    class PgException {
+    public:
+        PgException(const char *msg)
+            : message(msg)
+        {}
+        PgException(std::string msg)
+             : message(std::move(msg))
+        {}
+       
+        
+    private:
+        std::string message;
+        
+    };
+    
+    class PgResultError: public PgException {
+    public:
+        PgResultError(std::string msg, std::string result_code)
+            : PgException(std::move(msg))
+        {}
+    };
+    
+    class PgConnectionError: public PgResultError, std::runtime_error {
+        PgConnectionError(const std::string &msg, std::string result_code)
+            : PgResultError(msg, std::move(result_code))
+            , std::runtime_error(msg)
+        {}
+        
+    };
+    
+    
+ 
+/* postgresq error classes
+ *
+ * success
+ * warning
+ * no data
+ *
+ * 03 sql statement not yet  complete
+ * 08 connection exception -> could be resolved by reconnecting / resetting connection
+ * 09 triggered action exception
+ * 0A feature not supported
+ * 0B invalid transaction initiation
+ * 0F locator exception
+ * 0L invalid grantor
+ * 0P invalid role
+ * 0Z diagnostic exception
+ * 20 case not fount
+ * 21 cardinality violation
+ * 22 data exception
+ * 23 integrity constraint error
+ * 24 invalid cursor statement
+ * 25 invalid transaction state
+ * 26 invalid sql statement name
+ * 27 triggered data change violation
+ * 28 invalid authorization specification
+ * 2B Dependent Privilege Descriptors Still Exist
+ * 2D Invalid Transaction Termination
+ * 2F SQL Routine Exception
+ * 34 Invalid Cursor Name
+ * 38 External Routine Exception
+ * 39 External Routine Invocation Exception
+ * 3B Savepoint Exception
+ * 3D Invalid Catalog Name 
+ * 3F Invalid Schema Name
+ * 40 Transaction Rollback
+ * 42 Syntax Error or Access Rule Violation
+ * 44 WITH CHECK OPTION Violation
+ * 53 Insufficient Resources
+ * 54 Program Limit Exceeded
+ * 55 Object Not In Prerequisite State
+ * 57 Operator Intervention
+ * 58 System Error (errors external to PostgreSQL itself)
+ * 72 Snapshot Failure
+ * F0 Configuration File Error
+ * HV Foreign Data Wrapper Error (SQL/MED)
+ * P0 PL/pgSQL Error
+ * XX Internal Error
+ * 
+ * At what levels can the communication with postgresql fail
+ * - network -> reset/reconnecting
+ * - 
+ */
+}
+
+#endif // PGEXCEPTION_H

pgsql/pgsql.pro

@@ -34,6 +34,7 @@ release {
 
 SOURCES += Pgsql_Connection.cpp \
 	Pgsql_Params.cpp \
+	Pgsql_PgException.cpp \
     Pgsql_Result.cpp \
     Pgsql_Row.cpp \
     Pgsql_Value.cpp \ 
@@ -43,6 +44,7 @@ SOURCES += Pgsql_Connection.cpp \
 
 HEADERS  += Pgsql_Connection.h \
 	Pgsql_Params.h \
+	Pgsql_PgException.h \
     Pgsql_Result.h \
     Pgsql_Row.h \
     Pgsql_Value.h \