Merge branch 'MDL-65168' of git://github.com/stronk7/moodle

2025-08-05 17:06:53 +02:00 · 2019-04-03 16:42:41 +08:00 · 2019-04-03 16:42:41 +08:00 · ad4d995f19
commit ad4d995f19
parent dcdea70fca 71cbc0550f
7 changed files with 390 additions and 224 deletions
--- a/lib/classes/dml/table.php
+++ b/lib/classes/dml/table.php
@ -0,0 +1,133 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle 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 Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Helpers and methods relating to DML tables.
+ *
+ * @since      Moodle 3.7
+ * @package    core
+ * @category   dml
+ * @copyright  2019 Andrew Nicols <andrew@nicols.co.uk>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+namespace core\dml;
+
+use stdClass;
+
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ * Helpers and methods relating to DML tables.
+ *
+ * @copyright  2019 Andrew Nicols <andrew@nicols.co.uk>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class table {
+
+    /** @var string Name of the table that this class represents */
+    protected $tablename;
+
+    /** @var string Table alias */
+    protected $tablealias;
+
+    /** @var string Prefix to place before each field */
+    protected $fieldprefix;
+
+    /** @var array List of fields */
+    protected $fields;
+
+    /**
+     * Constructor for the table class.
+     *
+     * @param   string  $tablename The name of the table that this instance represents.
+     * @param   string  $tablealias The alias to use when selecting the table
+     * @param   string  $fieldprefix The prefix to use when selecting fields.
+     */
+    public function __construct(string $tablename, string $tablealias, string $fieldprefix) {
+        $this->tablename = $tablename;
+        $this->tablealias = $tablealias;
+        $this->fieldprefix = $fieldprefix;
+    }
+
+    /**
+     * Get the from TABLE ALIAS part of the FROM/JOIN string.
+     *
+     * @return  string
+     */
+    public function get_from_sql() : string {
+        return "{{$this->tablename}} {$this->tablealias}";
+    }
+
+    /**
+     * Get the list of fields in a table for use in preloading fields.
+     *
+     * @return  array       The list of columns in a table. The array key is the column name with an applied prefix.
+     */
+    protected function get_fieldlist() : array {
+        global $DB;
+
+        if (null === $this->fields) {
+            $fields = [];
+            foreach (array_keys($DB->get_columns($this->tablename)) as $fieldname) {
+                $fields["{$this->fieldprefix}{$fieldname}"] = $fieldname;
+            }
+
+            $this->fields = $fields;
+        }
+
+        return $this->fields;
+    }
+
+    /**
+     * Get the SELECT SQL to select a set of columns for this table.
+     *
+     * This function is intended to be used in combination with extract_from_result().
+     *
+     * @return  string      The SQL to use in the SELECT
+     */
+    public function get_field_select() : string {
+        $fieldlist = $this->get_fieldlist();
+
+        return implode(', ', array_map(function($fieldname, $fieldalias) {
+            return "{$this->tablealias}.{$fieldname} AS {$fieldalias}";
+        }, $fieldlist, array_keys($fieldlist)));
+    }
+
+    /**
+     * Extract fields from the specified result. The fields are removed from the original object.
+     *
+     * This function is intended to be used in combination with get_field_select().
+     *
+     * @param   stdClass    $result The result retrieved from the database with fields to be extracted
+     * @return  stdClass    The extracted result
+     */
+    public function extract_from_result(stdClass $result) : stdClass {
+        $record = new stdClass();
+
+        $fieldlist = $this->get_fieldlist();
+        foreach ($fieldlist as $fieldalias => $fieldname) {
+            if (property_exists($result, $fieldalias)) {
+                $record->$fieldname = $result->$fieldalias;
+                unset($result->$fieldalias);
+            } else {
+                debugging("Field '{$fieldname}' not found", DEBUG_DEVELOPER);
+            }
+        }
+
+        return $record;
+    }
+}