src/midgard_core_query_builder.c

/* 
 * Copyright (c) 2005 Jukka Zitting <jz@yukatan.fi>
 * Copyright (C) 2006 Piotr Pokora <piotrek.pokora@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <config.h>
#include "midgard/midgard_schema.h"
#include "midgard/midgard_legacy.h"
#include "midgard_core_query_builder.h"
#include "midgard/query_builder.h"
#include "query_constraint.h"
#include "simple_constraint.h"
#include "group_constraint.h"
#include "query_order.h"
#include "midgard/midgard_object_property.h"
#include "midgard/midgard_object.h"
#include "schema.h"
#include "midgard_mysql.h"

gchar *_midgard_core_qb_get_sql(
                MidgardQueryBuilder *builder, guint mode, gchar *select)
{
        g_assert(builder);
        g_assert(builder->schema->table);    
        
        /* FIXME, error reporting needed */
        if(builder->error != 0) {
            g_warning("Can not create query");
            return NULL;
        }
        
        GString *sql = g_string_new("SELECT ");
        g_string_append(sql, select);
        g_free(select);
        const gchar *tables = builder->schema->query->tables; /* FIXME */
        if(builder->tables != NULL)
            tables = builder->tables;
        
        g_string_append(sql, " FROM ");
        g_string_append(sql, tables);
        g_string_append(sql, " WHERE ");
        while (g_slist_next(builder->stack) != NULL) {
                g_warning("Constraint groups not properly nested");
                GSList *item = builder->stack;
                builder->stack = g_slist_remove_link(builder->stack, item);
                g_slist_free_1(item);
        }
        midgard_query_constraint_add_sql(
                MIDGARD_QUERY_CONSTRAINT(builder->stack->data), sql);

        if (builder->schema->use_lang == 1) {
                g_string_append(sql, " AND ");
                g_string_append(sql, builder->schema->table);
                g_string_append(sql, ".id=");
                g_string_append(sql, builder->schema->table);
                g_string_append(sql, "_i.sid");  
               
                if(!builder->unset_lang) {

                        g_string_append(sql, " AND ");
                        g_string_append(sql, builder->schema->table);
                        /* Default behaviour , we get multilang records 
                         * with lang 0 and other lang set, thus we have 
                         * "full" list of objects , even some of them are 
                         * not translated yet.*/ 
                        if(builder->lang < 0) {
                                g_string_append_printf(sql,
                                                "_i.lang IN (%d, %d)",
                                                mgd_get_default_lang(builder->mgd),
                                                mgd_lang(builder->mgd));        
                        } else {
                                /* builder->lang is set with set_lang method, so 
                                 * we get only those records with lang being set
                                 * and we ignore all others , even woth lang 0 
                                 */
                                g_string_append_printf(sql,
                                                "_i.lang = %d ",
                                                builder->lang);
                        }
                }
               
        }           

        if (builder->join != NULL){
                gchar *tmpstr = g_string_free(builder->join, FALSE);
                g_string_append(sql, tmpstr);
                g_free(tmpstr);
                builder->join = NULL;
        }

        if (!mgd_isroot(builder->mgd)) {
                g_string_append(sql, " AND ");
                g_string_append(sql, builder->schema->table);
                g_string_append_printf(
                        sql, ".sitegroup IN (0, %u)",
                        builder->mgd->current_user->sitegroup);
        }

        if(!builder->include_deleted) {
                g_string_append(sql, " AND ");
                g_string_append_printf(sql,
                                " %s.metadata_deleted = FALSE",
                                builder->schema->table);
        }
        /* TODO: The following code adds the ORDER BY ordering
         * constraints to the SQL query. Commented out because
         * I'm not sure about the correct "table.field" format
         * to use for field references. /2005-06-16 JZ
         */
        int i;
        for (i = 0; mode < MQB_SELECT_COUNT  && i < builder->orders->len; i++) {
                if (i > 0) {
                        g_string_append(sql, ", ");
                } else {
                        g_string_append(sql, " ORDER BY ");
                }
                MidgardQueryOrder *order = g_array_index(
                        builder->orders, MidgardQueryOrder*, i);        
                g_string_append(sql, midgard_query_order_get_sql(order));
        }

        if (mode < MQB_SELECT_COUNT && builder->limit != G_MAXUINT) {
                g_string_append_printf(sql, " LIMIT %u", builder->limit);
                if (builder->offset != 0) {
                        g_string_append_printf(
                                sql, " OFFSET %u", builder->offset);
                }
        }

        return g_string_free(sql, FALSE);
}

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