Remove duplication in ODBC::Connection constructors

Remove pointless specialisation on _Column for strings
Set cursor type to scrollable (required to refetch a row)
Resize binds if fetched data is truncated
Support scrolling fetch (default is old 'next record' behaviour)

8 files changed, 68 insertions, 46 deletions

diff --git a/libodbcpp/bind.h b/libodbcpp/bind.h
index 5baa53a..fd69900 100644
--- a/libodbcpp/bind.h
+++ b/libodbcpp/bind.h
@@ -11,7 +11,7 @@ namespace ODBC {
 			BindBase();
 			virtual			~BindBase() {}
 		protected:
-			SQLINTEGER		bindLen;			// Used memory
+			SQLLEN			bindLen;			// Used memory
 			friend class Param;
 			friend class Column;
 			friend class Command;
@@ -23,12 +23,6 @@ namespace ODBC {
 			mutable t		value;
 	};
 	typedef std::vector<char> SQLCHARVEC;
-	template <>
-	class Bind<SQLCHARVEC> {
-		public:
-			virtual			~Bind() {}
-			mutable SQLCHARVEC	value;
-	};
 }
 
 #endif
diff --git a/libodbcpp/column.cpp b/libodbcpp/column.cpp
index 6e517a6..3d37e50 100644
--- a/libodbcpp/column.cpp
+++ b/libodbcpp/column.cpp
@@ -1,3 +1,4 @@
+#include <sqlext.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include "column.h"
@@ -17,6 +18,21 @@ ODBC::Column::~Column()
 	delete composeCache;
 }
 
+void
+ODBC::Column::resize(SQLHANDLE hStmt)
+{
+}
+
+void
+ODBC::StringColumn::resize(SQLHANDLE hStmt)
+{
+	if (bindSize < bindLen) {
+		value.resize(bindLen + 1);
+		bindSize = bindLen;
+		bind(hStmt, colNo + 1, SQL_C_CHAR, &value[0], bindSize + 1);
+	}
+}
+
 bool
 ODBC::Column::isNull() const
 {
diff --git a/libodbcpp/column.h b/libodbcpp/column.h
index 67dd0c4..c9e65ca 100644
--- a/libodbcpp/column.h
+++ b/libodbcpp/column.h
@@ -10,6 +10,7 @@ namespace ODBC {
 			Column(const Glib::ustring &, unsigned int);
 			virtual			~Column();
 			void			bind(SQLHANDLE, SQLUINTEGER, SQLSMALLINT, void*, size_t);
+			virtual void	resize(SQLHANDLE);
 			operator int () const;
 			operator unsigned int () const;
 			operator long long () const;
@@ -32,8 +33,7 @@ namespace ODBC {
 			const Glib::ustring		name;
 		protected:
 			mutable Glib::ustring * composeCache;
-		private:
-			SQLUINTEGER		bindSize;			// Allocated memory
+			SQLLEN			bindSize;			// Allocated memory
 			friend class SelectCommand;
 	};
 	template <class t>
@@ -47,6 +47,12 @@ namespace ODBC {
 			int				writeToBuf(char ** buf) const;
 			int				writeToBuf(char ** buf, const char * fmt) const;
 	};
+	class StringColumn : public _Column<SQLCHARVEC> {
+		public:
+			StringColumn(const Glib::ustring & n, unsigned int i) :
+				_Column<SQLCHARVEC>(n, i) { }
+			void resize(SQLHANDLE);
+	};
 }
 
 void operator << (SQL_TIMESTAMP_STRUCT & target, const struct tm &);
diff --git a/libodbcpp/command.cpp b/libodbcpp/command.cpp
index 4ceb825..50dd679 100644
--- a/libodbcpp/command.cpp
+++ b/libodbcpp/command.cpp
@@ -11,6 +11,10 @@ ODBC::Command::Command(const Connection & c, const std::string & s) :
 	if (rc != SQL_SUCCESS) {
 		throw Error(rc, SQL_HANDLE_STMT, hStmt, "Allocate statement handle");
 	}
+	rc = SQLSetStmtAttr(hStmt, SQL_ATTR_CURSOR_TYPE, (SQLPOINTER)SQL_CURSOR_DYNAMIC, 0);
+	if ((rc != SQL_SUCCESS)) {
+		throw ConnectionError(rc, SQL_HANDLE_STMT, hStmt, "Set scrollable cursor");
+	}
     rc = SQLPrepare(hStmt, (SQLCHAR*)sql.c_str(), sql.length());
     if (rc != SQL_SUCCESS) {
         SQLFreeHandle(SQL_HANDLE_STMT, hStmt);
diff --git a/libodbcpp/connection.cpp b/libodbcpp/connection.cpp
index ef8fdbb..79c0f9d 100644
--- a/libodbcpp/connection.cpp
+++ b/libodbcpp/connection.cpp
@@ -11,6 +11,18 @@ ODBC::Connection::Connection(const DSN& d) :
 	txDepth(0),
 	txAborted(false)
 {
+	connectPre();
+	RETCODE dberr = SQLConnect(conn, (SQLCHAR*)d.dsn.c_str(), SQL_NTS,
+			(SQLCHAR*)d.username.c_str(), SQL_NTS, (SQLCHAR*)d.password.c_str(), SQL_NTS);
+	if ((dberr != SQL_SUCCESS)) {
+		throw ConnectionError(dberr, SQL_HANDLE_DBC, conn, "Connect");
+	}
+	connectPost();
+}
+
+void
+ODBC::Connection::connectPre()
+{
 	SQLRETURN dberr = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &env);
 	if ((dberr != SQL_SUCCESS)) {
 		throw ConnectionError(dberr, SQL_HANDLE_ENV, env, "Allocate handle");
@@ -30,14 +42,12 @@ ODBC::Connection::Connection(const DSN& d) :
 	if ((dberr != SQL_SUCCESS)) {
 		throw ConnectionError(dberr, SQL_HANDLE_ENV, env, "Set connection attributes");
 	}
+}
 
-	dberr = SQLConnect(conn, (SQLCHAR*)d.dsn.c_str(), SQL_NTS,
-			(SQLCHAR*)d.username.c_str(), SQL_NTS, (SQLCHAR*)d.password.c_str(), SQL_NTS);
-	if ((dberr != SQL_SUCCESS)) {
-		throw ConnectionError(dberr, SQL_HANDLE_DBC, conn, "Connect");
-	}
-
-	dberr = SQLSetConnectOption(conn, SQL_ATTR_AUTOCOMMIT, SQL_AUTOCOMMIT_ON);
+void
+ODBC::Connection::connectPost()
+{
+	RETCODE dberr = SQLSetConnectOption(conn, SQL_ATTR_AUTOCOMMIT, SQL_AUTOCOMMIT_ON);
 	if ((dberr != SQL_SUCCESS)) {
 		throw ConnectionError(dberr, SQL_HANDLE_DBC, conn, "Set default auto commit");
 	}
@@ -49,35 +59,12 @@ ODBC::Connection::Connection(const std::string & s) :
 	txDepth(0),
 	txAborted(false)
 {
-	SQLRETURN dberr = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &env);
-	if ((dberr != SQL_SUCCESS)) {
-		throw ConnectionError(dberr, SQL_HANDLE_ENV, env, "Allocate handle");
-	}
-
-	dberr = SQLSetEnvAttr(env, SQL_ATTR_ODBC_VERSION, (void *) SQL_OV_ODBC3, 0);
-	if ((dberr != SQL_SUCCESS)) {
-		throw ConnectionError(dberr, SQL_HANDLE_ENV, env, "Set ODBC version");
-	}
-
-	dberr = SQLAllocHandle(SQL_HANDLE_DBC, env, &conn);
-	if ((dberr != SQL_SUCCESS)) {
-		throw ConnectionError(dberr, SQL_HANDLE_ENV, env, "Allocate DBC handle");
-	}
-
-	dberr = SQLSetConnectAttr(conn, SQL_LOGIN_TIMEOUT, (SQLPOINTER *)5, 0);
-	if ((dberr != SQL_SUCCESS)) {
-		throw ConnectionError(dberr, SQL_HANDLE_ENV, env, "Set connection attributes");
-	}
-
-	dberr = SQLDriverConnect(conn, NULL, (SQLCHAR*)s.c_str(), s.length(), NULL, 0, NULL, SQL_DRIVER_NOPROMPT);
+	connectPre();
+	RETCODE dberr = SQLDriverConnect(conn, NULL, (SQLCHAR*)s.c_str(), s.length(), NULL, 0, NULL, SQL_DRIVER_NOPROMPT);
 	if ((dberr != SQL_SUCCESS)) {
 		throw ConnectionError(dberr, SQL_HANDLE_DBC, conn, "Connect");
 	}
-
-	dberr = SQLSetConnectOption(conn, SQL_ATTR_AUTOCOMMIT, SQL_AUTOCOMMIT_ON);
-	if ((dberr != SQL_SUCCESS)) {
-		throw ConnectionError(dberr, SQL_HANDLE_DBC, conn, "Set default auto commit");
-	}
+	connectPost();
 }
 
 ODBC::Connection::~Connection()
diff --git a/libodbcpp/connection.h b/libodbcpp/connection.h
index 0d2e9d4..86ff7d8 100644
--- a/libodbcpp/connection.h
+++ b/libodbcpp/connection.h
@@ -24,6 +24,8 @@ namespace ODBC {
 			SQLINTEGER		getAttrInt(SQLINTEGER) const;
 
 		private:
+			void			connectPre();
+			void			connectPost();
 			mutable unsigned int	txDepth;
 			mutable bool			txAborted;
 	};
diff --git a/libodbcpp/selectcommand.cpp b/libodbcpp/selectcommand.cpp
index 88a071f..3b903d6 100644
--- a/libodbcpp/selectcommand.cpp
+++ b/libodbcpp/selectcommand.cpp
@@ -3,6 +3,7 @@
 #include "column.h"
 #include <sqlext.h>
 #include <stdio.h>
+#include <string.h>
 
 ODBC::SelectCommand::SelectCommand(const Connection & c, const std::string & s) :
 	Command(c, s)
@@ -26,12 +27,12 @@ ODBC::SelectCommand::~SelectCommand()
 }
 
 bool
-ODBC::SelectCommand::fetch()
+ODBC::SelectCommand::fetch(SQLSMALLINT orientation, SQLLEN offset)
 {
 	if (columns.size() == 0) {
 		execute();
 	}
-	RETCODE rc = SQLFetch(hStmt);
+	RETCODE rc = SQLFetchScroll(hStmt, orientation, offset);
 	switch (rc) {
 		case SQL_SUCCESS:
 			for (Columns::iterator i = columns.begin(); i != columns.end(); i++) {
@@ -42,6 +43,18 @@ ODBC::SelectCommand::fetch()
 		case SQL_NO_DATA:
 			return false;
 		default:
+			{
+				SQLCHAR sqlstatus[5];
+				RETCODE diagrc = SQLGetDiagRec(SQL_HANDLE_STMT, hStmt, 1, sqlstatus, NULL, NULL, 0, NULL);
+				if (SQL_SUCCEEDED(diagrc)) {
+					if (!strncmp((const char*)sqlstatus, "01004", 5)) {
+						for (Columns::iterator i = columns.begin(); i != columns.end(); i++) {
+							(*i)->resize(hStmt);
+						}
+						return fetch(SQL_FETCH_RELATIVE, 0);
+					}
+				}
+			}
 			throw Error(rc, SQL_HANDLE_STMT, hStmt, "%s: SQLFetch",
 					__FUNCTION__);
 	}
@@ -87,7 +100,7 @@ ODBC::SelectCommand::execute()
 			case SQL_VARCHAR:
 			case SQL_LONGVARCHAR:
 				{
-					_Column<SQLCHARVEC>* s = new _Column<SQLCHARVEC>(colName, col);
+					StringColumn* s = new StringColumn(colName, col);
 					s->value.resize(bindSize + 1);
 					s->bind(hStmt, sqlcol, SQL_C_CHAR, &s->value[0], bindSize + 1);
 					columns[col] = s;
diff --git a/libodbcpp/selectcommand.h b/libodbcpp/selectcommand.h
index 541cd08..c523f25 100644
--- a/libodbcpp/selectcommand.h
+++ b/libodbcpp/selectcommand.h
@@ -10,7 +10,7 @@ namespace ODBC {
 		public:
 			SelectCommand (const Connection &, const std::string & sql);
 			~SelectCommand();
-			bool				fetch();
+			bool				fetch(SQLSMALLINT orientation = SQL_FETCH_NEXT, SQLLEN offset = 0);
 			const Column &		operator[](unsigned int col) const;
 			const Column &		operator[](const Glib::ustring &) const;
 			unsigned int		columnCount() const;