From 832e89440f2586a2b027dfa56e5d14baf9ecd188 Mon Sep 17 00:00:00 2001
From: Douglas Heriot <douglas@douglasheriot.com>
Date: Thu, 26 May 2016 00:34:34 +1000
Subject: [PATCH] Better exception messages when statements fail

Added new constructor to Exception that takes sqlite3* pointer, allowing for getting more information out. Makes it much easier to debug syntax errors in prepared statements, for example.
---
 include/SQLiteCpp/Exception.h | 33 ++++++++++++++++++++++++++++++++-
 include/SQLiteCpp/Statement.h |  2 +-
 src/Statement.cpp             |  4 ++--
 3 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/include/SQLiteCpp/Exception.h b/include/SQLiteCpp/Exception.h
index ae7a8ed..d58915e 100644
--- a/include/SQLiteCpp/Exception.h
+++ b/include/SQLiteCpp/Exception.h
@@ -12,6 +12,8 @@
 
 #include <stdexcept>
 #include <string>
+#include <sstream>
+#include <sqlite3.h>
 
 
 namespace SQLite
@@ -30,9 +32,38 @@ public:
      * @param[in] aErrorMessage The string message describing the SQLite error
      */
     explicit Exception(const std::string& aErrorMessage) :
-        std::runtime_error(aErrorMessage)
+        std::runtime_error(aErrorMessage),
+        errcode(0),
+        extendedErrcode(0),
+        errstr(),
+        errmsg()
     {
     }
+    
+    /**
+     * @brief Encapsulation of the error message from SQLite3, based on std::runtime_error.
+     *
+     * @param[in] apSQLite The SQLite object, to obtain detailed error messages from.
+     * @param[in] ret Return value from function call that failed.
+     */
+    explicit Exception(sqlite3* apSQLite, int ret) :
+        errcode(ret),
+        extendedErrcode(sqlite3_extended_errcode(apSQLite)),
+        errstr(sqlite3_errstr(ret)),
+        errmsg(sqlite3_errmsg(apSQLite)),
+        
+        std::runtime_error([apSQLite, ret](){
+            std::ostringstream message;
+            message << sqlite3_errstr(ret) << ": " << sqlite3_errmsg(apSQLite);
+            return message.str();
+        }())
+    {
+    }
+    
+    const int errcode;
+    const int extendedErrcode;
+    const std::string errstr;
+    const std::string errmsg;
 };
 
 
diff --git a/include/SQLiteCpp/Statement.h b/include/SQLiteCpp/Statement.h
index 3ee3162..dc44b6e 100644
--- a/include/SQLiteCpp/Statement.h
+++ b/include/SQLiteCpp/Statement.h
@@ -457,7 +457,7 @@ private:
     {
         if (SQLITE_OK != aRet)
         {
-            throw SQLite::Exception(sqlite3_errstr(aRet));
+            throw SQLite::Exception(mStmtPtr, aRet);
         }
     }
 
diff --git a/src/Statement.cpp b/src/Statement.cpp
index 20d4bc5..f8db0c2 100644
--- a/src/Statement.cpp
+++ b/src/Statement.cpp
@@ -227,7 +227,7 @@ int Statement::exec()
         {
             mbOk = false;
             mbDone = false;
-            throw SQLite::Exception(sqlite3_errstr(ret));
+            throw SQLite::Exception(mStmtPtr, ret);
         }
     }
     else
@@ -317,7 +317,7 @@ Statement::Ptr::Ptr(sqlite3* apSQLite, std::string& aQuery) :
     const int ret = sqlite3_prepare_v2(apSQLite, aQuery.c_str(), static_cast<int>(aQuery.size()), &mpStmt, NULL);
     if (SQLITE_OK != ret)
     {
-        throw SQLite::Exception(sqlite3_errstr(ret));
+        throw SQLite::Exception(apSQLite, ret);
     }
     // Initialize the reference counter of the sqlite3_stmt :
     // used to share the mStmtPtr between Statement and Column objects;