[libgda/metat: 6/9] provider-meta: added utility methods to run queries

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit 7b6c2dd50a1b463f8dee633760aa85b48190a1d1
Author: Daniel Espinosa <esodan gmail com>
Date:   Mon Aug 20 14:46:30 2018 -0500

    provider-meta: added utility methods to run queries

 libgda/gda-provider-meta.c          | 77 +++++++++++++++++++++++++++++++++++++
 libgda/gda-provider-meta.h          | 14 +++++++
 libgda/sqlite/gda-sqlite-provider.c |  2 +
 3 files changed, 93 insertions(+)
---
diff --git a/libgda/gda-provider-meta.c b/libgda/gda-provider-meta.c
index 74764af1b..90c42faa7 100644
--- a/libgda/gda-provider-meta.c
+++ b/libgda/gda-provider-meta.c
@@ -18,6 +18,16 @@
  */
 #include <libgda/gda-provider-meta.h>
 #include <libgda/gda-connection.h>
+#include <glib/gi18n-lib.h>
+
+/* module error */
+GQuark gda_provider_meta_error_quark (void)
+{
+  static GQuark quark;
+  if (!quark)
+          quark = g_quark_from_static_string ("gda_provider_meta_error");
+  return quark;
+}
 
 enum {
   PROP_CONNECTION = 1,
@@ -42,6 +52,73 @@ gda_provider_meta_default_init (GdaProviderMetaInterface *iface) {
                                      obj_properties[PROP_CONNECTION]);
 }
 
+/**
+ * gda_provider_meta_execute_query:
+ * @prov: a #GdaProviderMeta
+ * @sql: a string with the SQL to execute on provider
+ * @error: place to store errors or %NULL
+ *
+ * SQL is specific for current provider.
+ *
+ * Returns: (transfer full) (nullable): a new #GdaDataModel with as a result of the query
+ * Since: 6.0
+ * Stability: Unstable
+ */
+GdaDataModel  *gda_provider_meta_execute_query (GdaProviderMeta *prov,
+                                                const gchar *sql,
+                                                GError **error)
+{
+  g_return_val_if_fail (prov, NULL);
+  g_return_val_if_fail (GDA_IS_PROVIDER_META (prov), NULL);
+  g_return_val_if_fail (sql, NULL);
+
+  GdaDataModel *model = NULL;
+  GdaConnection *cnc = NULL;
+  g_object_get (G_OBJECT (prov), "connection", &cnc, NULL);
+  if (cnc == NULL) {
+    g_set_error (error, GDA_PROVIDER_META_ERROR, GDA_PROVIDER_META_NO_CONNECTION_ERROR,
+                 _("No connection is set"));
+    return NULL;
+  }
+  if (!gda_connection_is_opened (cnc)) {
+    g_set_error (error, GDA_PROVIDER_META_ERROR, GDA_PROVIDER_META_NO_CONNECTION_ERROR,
+                 _("Connection is no opened"));
+    return NULL;
+  }
+  model = gda_connection_execute_select_command (cnc, sql, error);
+  return model;
+}
+
+/**
+ * gda_provider_meta_execute_query:
+ * @prov: a #GdaProviderMeta
+ * @sql: a string with the SQL to execute on provider
+ * @error: place to store errors or %NULL
+ *
+ * SQL is specific for current provider.
+ *
+ * Returns: (transfer full) (nullable): a new #GdaDataModel with as a result of the query
+ * Since: 6.0
+ * Stability: Unstable
+ */
+GdaRow*
+gda_provider_meta_execute_query_row (GdaProviderMeta *prov,
+                                     const gchar *sql,
+                                     GError **error)
+{
+  GdaDataModel *model = NULL;
+  model = gda_provider_meta_execute_query (prov, sql, error);
+  if (model == NULL) {
+    return NULL;
+  }
+  if (gda_data_model_get_n_rows (model) != 1) {
+    g_set_error (error, GDA_PROVIDER_META_ERROR, GDA_PROVIDER_META_NO_CONNECTION_ERROR,
+                 _("No rows or more than one row was returned from query"));
+    return NULL;
+  }
+  return gda_row_new_from_data_model (model, 0);
+}
+
 /**
  * gda_provider_meta_get_connection:
  * @prov:
diff --git a/libgda/gda-provider-meta.h b/libgda/gda-provider-meta.h
index 35b304e6b..557c5bbe7 100644
--- a/libgda/gda-provider-meta.h
+++ b/libgda/gda-provider-meta.h
@@ -25,6 +25,13 @@
 
 G_BEGIN_DECLS
 
+typedef enum {
+       GDA_PROVIDER_META_NO_CONNECTION_ERROR
+} GdaProviderMetaError;
+
+extern GQuark gda_provider_meta_error_quark (void);
+#define GDA_PROVIDER_META_ERROR gda_provider_meta_error_quark ()
+
 #define GDA_TYPE_PROVIDER_META gda_provider_meta_get_type()
 
 G_DECLARE_INTERFACE(GdaProviderMeta, gda_provider_meta, GDA, PROVIDER_META, GObject)
@@ -229,6 +236,13 @@ struct _GdaProviderMetaInterface
   gpointer padding[12];
 };
 
+GdaDataModel  *gda_provider_meta_execute_query        (GdaProviderMeta *prov,
+                                                       const gchar *sql,
+                                                       GError **error);
+
+GdaRow        *gda_provider_meta_execute_query_row    (GdaProviderMeta *prov,
+                                                       const gchar *sql,
+                                                       GError **error);
 
 GdaConnection *gda_provider_meta_get_connection       (GdaProviderMeta *prov);
 
diff --git a/libgda/sqlite/gda-sqlite-provider.c b/libgda/sqlite/gda-sqlite-provider.c
index c4774752f..ec36fa1e3 100644
--- a/libgda/sqlite/gda-sqlite-provider.c
+++ b/libgda/sqlite/gda-sqlite-provider.c
@@ -65,6 +65,7 @@
 #include <stdio.h>
 #define _GDA_PSTMT(x) ((GdaPStmt*)(x))
 #include <libgda/gda-debug-macros.h>
+#include <libgda/gda-provider-meta.h>
 
 #define FILE_EXTENSION ".db"
 static gchar *get_table_nth_column_name (GdaConnection *cnc, const gchar *table_name, gint pos);
@@ -3995,3 +3996,4 @@ gda_sqlite_provider_unescape_string (G_GNUC_UNUSED GdaServerProvider *provider,
 
        return retval;
 }
+