[libgdamm] SqlBuilder: Add SqlError and fix select_add_target() with no alias.

[Murray Cumming <murrayc src gnome org>]

commit 8af75c8b7f9efe1d373d6f31a449fe12d8b03134
Author: Murray Cumming <murrayc murrayc com>
Date:   Sat Feb 27 00:58:17 2010 +0100

    SqlBuilder: Add SqlError and fix select_add_target() with no alias.
    
    * libgda/src/sqlbuilder.[hg|ccg]: Add SqlError to wrap the GdaSqlError
    error domain thrown (but not documented) by SqlBuilder.
    select_add_target(): Avoid passing a  alias. I have fixed the C
    function in libgda but this makes it safe even when that is not deployed.

 ChangeLog                 |    9 +++++++++
 libgda/src/sqlbuilder.ccg |   11 ++++++++++-
 libgda/src/sqlbuilder.hg  |    3 ++-
 3 files changed, 21 insertions(+), 2 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index a276f07..04013b8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2010-02-27  Murray Cumming  <murrayc murrayc com>
+
+  SqlBuilder: Add SqlError and fix select_add_target() with no alias.
+  
+	* libgda/src/sqlbuilder.[hg|ccg]: Add SqlError to wrap the GdaSqlError 
+	error domain thrown (but not documented) by SqlBuilder.
+	select_add_target(): Avoid passing a "" alias. I have fixed the C 
+	function in libgda but this makes it safe even when that is not deployed.
+
 3.99.19:
 
 2010-02-25  Murray Cumming  <murrayc murrayc com>
diff --git a/libgda/src/sqlbuilder.ccg b/libgda/src/sqlbuilder.ccg
index 6c4cbff..1a2c671 100644
--- a/libgda/src/sqlbuilder.ccg
+++ b/libgda/src/sqlbuilder.ccg
@@ -30,6 +30,15 @@ namespace Gnome
 namespace Gda
 {
 
+//TODO: Put this in glibmm and use it generally:
+static const char* string_or_null(const Glib::ustring& str)
+{
+  if(str.empty())
+    return 0; //Avoid returning "", because not all C functions check for it properly.
+  else
+    return str.c_str();
+}
+
 SqlBuilder::SqlBuilder(SqlStatementType type)
   : _CONSTRUCT("stmt-type", type)
 {
@@ -73,7 +82,7 @@ guint SqlBuilder::add_function(const Glib::ustring& function_name, const Glib::A
 
 guint SqlBuilder::select_add_target(const Glib::ustring& table_name, const Glib::ustring& alias)
 {
-  return gda_sql_builder_select_add_target(gobj(), table_name.c_str(), alias.c_str());
+  return gda_sql_builder_select_add_target(gobj(), table_name.c_str(), string_or_null(alias.c_str()));
 }
 
 
diff --git a/libgda/src/sqlbuilder.hg b/libgda/src/sqlbuilder.hg
index f7bef2f..2c3dd83 100644
--- a/libgda/src/sqlbuilder.hg
+++ b/libgda/src/sqlbuilder.hg
@@ -33,6 +33,7 @@ namespace Gda
 _WRAP_ENUM(SqlOperatorType, GdaSqlOperatorType)
 _WRAP_ENUM(SqlSelectJoinType, GdaSqlSelectJoinType)
 _WRAP_GERROR(SqlBuilderError, GdaSqlBuilderError, GDA_SQL_BUILDER_ERROR)
+_WRAP_GERROR(SqlError, GdaSqlErrorType, GDA_SQL_ERROR)
 
 /*
  * @ingroup Connection
@@ -152,7 +153,7 @@ public:
    */
   guint select_add_target(const Glib::ustring& table_name, const Glib::ustring& alias = Glib::ustring());
 
-  _IGNORE(gda_sql_builder_select_add_target_id)
+  _IGNORE(gda_sql_builder_select_add_target_id, gda_sql_builder_select_add_target)
 
   /** Joins two targets in a SELECT statement
    * @param left_target_id The ID of the left target to use (not %0)