[evolution-data-server/sqlite-refactor] EBookSqlite: Experimental query formation change

[Tristan Van Berkom <tvb src gnome org>]

commit 0eb19ea56840c18d7441e8c117a5d5e3036cad10
Author: Tristan Van Berkom <tristanvb openismus com>
Date:   Sat Nov 30 15:40:11 2013 +0900

    EBookSqlite: Experimental query formation change

 addressbook/libedata-book/e-book-sqlite.c |   75 +++++++----------------------
 1 files changed, 17 insertions(+), 58 deletions(-)
---
diff --git a/addressbook/libedata-book/e-book-sqlite.c b/addressbook/libedata-book/e-book-sqlite.c
index 923da63..2da05e4 100644
--- a/addressbook/libedata-book/e-book-sqlite.c
+++ b/addressbook/libedata-book/e-book-sqlite.c
@@ -4882,7 +4882,7 @@ query_preflight (PreflightContext   *context,
                        query_preflight_substitute_full_name (context, ebsql);
 
                        /* Optimize queries which touch auxiliary columns */
-                       query_preflight_optimize (context, ebsql);
+                       /* query_preflight_optimize (context, ebsql); */
                } else {
 
                        /* We might use this context to perform a fallback query,
@@ -5354,6 +5354,15 @@ ebsql_generate_constraints (EBookSqlite *ebsql,
        sub_query_context_free (ctx);
 }
 
+
+/* SELECT DISTINCT summary.uid, summary.vcard FROM folder_id AS summary */
+/* JOIN folder_id_phone_list AS phone_list */
+/*      ON phone_list.uid = summary.uid */
+/* JOIN folder_id_email_list AS email_list */
+/*      ON email_list.uid = summary.uid */
+/* WHERE phone_list.value LIKE '%0505'  AND email_list.value LIKE 'eddie%'; */
+
+
 /* Generates the SELECT portion of the query, this will possibly add some
  * of the constraints into nested selects. Constraints that could not be
  * nested will have their symbolic table names in context.
@@ -5370,7 +5379,6 @@ ebsql_generate_select (EBookSqlite *ebsql,
 {
        GSList *l;
        EbSqlRowFunc callback = NULL;
-       gchar *previous_field = NULL;
 
        g_string_append (string, "SELECT ");
        if (context->aux_fields)
@@ -5400,69 +5408,20 @@ ebsql_generate_select (EBookSqlite *ebsql,
                break;
        }
 
-       g_string_append (string, "FROM ");
+       ebsql_string_append_printf (string, "FROM %Q AS summary", ebsql->priv->folderid);
 
        for (l = context->aux_fields; l; l = l->next) {
                PreflightAuxData *aux_data = (PreflightAuxData *)l->data;
                SummaryField     *field    = summary_field_get (ebsql, aux_data->field_id);
 
-               /* For every other query, start with the JOIN */
-               if (previous_field)
-                       g_string_append (string, "LEFT OUTER JOIN ");
-
-               if (aux_data->constraints) {
-                       /* Each nested select must be outer left joined on to
-                        * the previous one, in this way the collection of joined
-                        * tables is equal to a logical AND.
-                        *
-                        * See query_preflight_optimize() for more details.
-                        */
-                       ebsql_string_append_printf (string,
-                                                   "( SELECT DISTINCT %s.uid FROM %Q AS %s WHERE ",
-                                                   field->aux_table_symbolic,
-                                                   field->aux_table,
-                                                   field->aux_table_symbolic);
-                       ebsql_generate_constraints (ebsql, string,
-                                                                 aux_data->constraints,
-                                                                 NULL);
-                       ebsql_string_append_printf (string, " ) AS %s_results ",
-                                                   field->aux_table_symbolic);
-
-                       if (previous_field)
-                               ebsql_string_append_printf (string, "ON %s_results.uid = %s ",
-                                                           field->aux_table_symbolic,
-                                                           previous_field);
-
-                       g_free (previous_field);
-                       previous_field = g_strconcat (field->aux_table_symbolic,
-                                                     "_results.uid", NULL);
 
-               } else {
-                       /* Join the table in the normal way and leave the constraints for later */
-                       ebsql_string_append_printf (string, "%Q AS %s ",
-                                                   field->aux_table,
-                                                   field->aux_table_symbolic);
-
-                       if (previous_field)
-                               ebsql_string_append_printf (string, "ON %s.uid = %s ",
-                                                           field->aux_table_symbolic,
-                                                           previous_field);
-
-                       g_free (previous_field);
-                       previous_field = g_strconcat (field->aux_table_symbolic,
-                                                     ".uid", NULL);
-               }
+               /* Join the table in the normal way and leave the constraints for later */
+               ebsql_string_append_printf (string, " JOIN %Q AS %s ON %s.uid = summary.uid",
+                                           field->aux_table,
+                                           field->aux_table_symbolic,
+                                           field->aux_table_symbolic);
        }
 
-       if (previous_field)
-               g_string_append (string, "LEFT OUTER JOIN ");
-
-       ebsql_string_append_printf (string, "%Q AS summary ", ebsql->priv->folderid);
-       if (previous_field)
-               ebsql_string_append_printf (string, "ON summary.uid = %s ", previous_field);
-
-       g_free (previous_field);
-
        return callback;
 }
 
@@ -5495,7 +5454,7 @@ ebsql_do_search_query (EBookSqlite *ebsql,
                /*
                 * Now generate the search expression on the main contacts table
                 */
-               g_string_append (string, "WHERE ");
+               g_string_append (string, " WHERE ");
                ebsql_generate_constraints (ebsql,
                                            string,
                                            context->constraints,