Initial commit of intern.ccwn.org contentsHEADmaster

1 files changed, 689 insertions, 0 deletions

diff --git a/hugo/tbl_relation.php b/hugo/tbl_relation.php
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+++ b/hugo/tbl_relation.php
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+<?php
+/* vim: set expandtab sw=4 ts=4 sts=4: */
+/**
+ * Display table relations for viewing and editing
+ *
+ * includes phpMyAdmin relations and InnoDB relations
+ *
+ * @todo fix name handling: currently names with dots (.) are not properly handled
+ * for internal relations (but foreign keys relations are correct)
+ * @todo foreign key constraints require both fields being of equal type and size
+ * @todo check foreign fields to be from same type and size, all other makes no sense
+ * @todo add an link to create an index required for constraints,
+ * or an option to do automatically
+ * @todo if above todos are fullfilled we can add all fields meet requirements
+ * in the select dropdown
+ * @package PhpMyAdmin
+ */
+
+/**
+ * Gets some core libraries
+ */
+require_once 'libraries/common.inc.php';
+require_once 'libraries/index.lib.php';
+
+$response = PMA_Response::getInstance();
+$header   = $response->getHeader();
+$scripts  = $header->getScripts();
+$scripts->addFile('tbl_relation.js');
+$scripts->addFile('indexes.js');
+
+/**
+ * Sets globals from $_POST
+ */
+$post_params = array(
+    'destination',
+    'destination_foreign',
+    'display_field',
+    'fields_name',
+    'on_delete',
+    'on_update'
+);
+
+foreach ($post_params as $one_post_param) {
+    if (isset($_POST[$one_post_param])) {
+        $GLOBALS[$one_post_param] = $_POST[$one_post_param];
+    }
+}
+
+/**
+ * Gets tables informations
+ */
+require_once 'libraries/tbl_info.inc.php';
+
+$options_array = array(
+    'CASCADE'   => 'CASCADE',
+    'SET_NULL'  => 'SET NULL',
+    'NO_ACTION' => 'NO ACTION',
+    'RESTRICT'  => 'RESTRICT',
+);
+
+/**
+ * Gets the relation settings
+ */
+$cfgRelation = PMA_getRelationsParam();
+
+/**
+ * Updates
+ */
+if ($cfgRelation['relwork']) {
+    $existrel = PMA_getForeigners($db, $table, '', 'internal');
+}
+if (PMA_Util::isForeignKeySupported($tbl_storage_engine)) {
+    $existrel_foreign = PMA_getForeigners($db, $table, '', 'foreign');
+}
+if ($cfgRelation['displaywork']) {
+    $disp     = PMA_getDisplayField($db, $table);
+}
+
+// will be used in the logic for internal relations and foreign keys:
+$multi_edit_columns_name = isset($_REQUEST['fields_name'])
+    ? $_REQUEST['fields_name']
+    : null;
+
+$html_output = '';
+
+// u p d a t e s   f o r   I n t e r n a l    r e l a t i o n s
+if (isset($destination) && $cfgRelation['relwork']) {
+
+    foreach ($destination as $master_field_md5 => $foreign_string) {
+        $upd_query = false;
+
+        // Map the fieldname's md5 back to its real name
+        $master_field = $multi_edit_columns_name[$master_field_md5];
+
+        if (! empty($foreign_string)) {
+            $foreign_string = trim($foreign_string, '`');
+            list($foreign_db, $foreign_table, $foreign_field)
+                = explode('.', $foreign_string);
+            if (! isset($existrel[$master_field])) {
+                $upd_query  = 'INSERT INTO '
+                    . PMA_Util::backquote($GLOBALS['cfgRelation']['db'])
+                    . '.' . PMA_Util::backquote($cfgRelation['relation'])
+                    . '(master_db, master_table, master_field, foreign_db,'
+                    . ' foreign_table, foreign_field)'
+                    . ' values('
+                    . '\'' . PMA_Util::sqlAddSlashes($db) . '\', '
+                    . '\'' . PMA_Util::sqlAddSlashes($table) . '\', '
+                    . '\'' . PMA_Util::sqlAddSlashes($master_field) . '\', '
+                    . '\'' . PMA_Util::sqlAddSlashes($foreign_db) . '\', '
+                    . '\'' . PMA_Util::sqlAddSlashes($foreign_table) . '\','
+                    . '\'' . PMA_Util::sqlAddSlashes($foreign_field) . '\')';
+            } elseif ($existrel[$master_field]['foreign_db'] . '.' .$existrel[$master_field]['foreign_table'] . '.' . $existrel[$master_field]['foreign_field'] != $foreign_string) {
+                $upd_query  = 'UPDATE '
+                    . PMA_Util::backquote($GLOBALS['cfgRelation']['db'])
+                    . '.' . PMA_Util::backquote($cfgRelation['relation']) . ' SET'
+                    . ' foreign_db       = \''
+                    . PMA_Util::sqlAddSlashes($foreign_db) . '\', '
+                    . ' foreign_table    = \''
+                    . PMA_Util::sqlAddSlashes($foreign_table) . '\', '
+                    . ' foreign_field    = \''
+                    . PMA_Util::sqlAddSlashes($foreign_field) . '\' '
+                    . ' WHERE master_db  = \'' . PMA_Util::sqlAddSlashes($db) . '\''
+                    . ' AND master_table = \''
+                    . PMA_Util::sqlAddSlashes($table) . '\''
+                    . ' AND master_field = \''
+                    . PMA_Util::sqlAddSlashes($master_field) . '\'';
+            } // end if... else....
+        } elseif (isset($existrel[$master_field])) {
+            $upd_query = 'DELETE FROM '
+                . PMA_Util::backquote($GLOBALS['cfgRelation']['db'])
+                . '.' . PMA_Util::backquote($cfgRelation['relation'])
+                . ' WHERE master_db  = \'' . PMA_Util::sqlAddSlashes($db) . '\''
+                . ' AND master_table = \'' . PMA_Util::sqlAddSlashes($table) . '\''
+                . ' AND master_field = \'' . PMA_Util::sqlAddSlashes($master_field)
+                . '\'';
+        } // end if... else....
+        if ($upd_query) {
+            PMA_queryAsControlUser($upd_query);
+        }
+    } // end while
+} // end if (updates for internal relations)
+
+// u p d a t e s    f o r    f o r e i g n    k e y s
+// (for now, one index name only; we keep the definitions if the
+// foreign db is not the same)
+
+if (isset($_REQUEST['destination_foreign'])) {
+    $display_query = '';
+    $seen_error = false;
+    foreach ($_REQUEST['destination_foreign'] as $master_field_md5 => $foreign_string) {
+        $create = false;
+        $drop = false;
+
+        // Map the fieldname's md5 back to it's real name
+        $master_field = $multi_edit_columns_name[$master_field_md5];
+
+        if (! empty($foreign_string)) {
+            list($foreign_db, $foreign_table, $foreign_field)
+                = PMA_backquoteSplit($foreign_string);
+            if (! isset($existrel_foreign[$master_field])) {
+                // no key defined for this field
+                $create = true;
+            } elseif (PMA_Util::backquote($existrel_foreign[$master_field]['foreign_db']) != $foreign_db
+                || PMA_Util::backquote($existrel_foreign[$master_field]['foreign_table']) != $foreign_table
+                || PMA_Util::backquote($existrel_foreign[$master_field]['foreign_field']) != $foreign_field
+                || $_REQUEST['constraint_name'][$master_field_md5] != $existrel_foreign[$master_field]['constraint']
+                || ($_REQUEST['on_delete'][$master_field_md5] != (! empty($existrel_foreign[$master_field]['on_delete']) ? $existrel_foreign[$master_field]['on_delete'] : 'RESTRICT'))
+                || ($_REQUEST['on_update'][$master_field_md5] != (! empty($existrel_foreign[$master_field]['on_update']) ? $existrel_foreign[$master_field]['on_update'] : 'RESTRICT'))
+            ) {
+                // another foreign key is already defined for this field
+                // or an option has been changed for ON DELETE or ON UPDATE
+                $drop = true;
+                $create = true;
+            } // end if... else....
+        } elseif (isset($existrel_foreign[$master_field])) {
+            $drop = true;
+        } // end if... else....
+
+        $tmp_error_drop = false;
+        if ($drop) {
+            $drop_query = PMA_getSQLToDropForeignKey(
+                $table, $existrel_foreign[$master_field]['constraint']
+            );
+            $display_query .= $drop_query . "\n";
+            PMA_DBI_try_query($drop_query);
+            $tmp_error_drop = PMA_DBI_getError();
+
+            if (! empty($tmp_error_drop)) {
+                $seen_error = true;
+                $html_output .= PMA_Util::mysqlDie(
+                    $tmp_error_drop, $drop_query, false, '', false
+                );
+                continue;
+            }
+        }
+        $tmp_error_create = false;
+        if ($create) {
+            $create_query = PMA_getSQLToCreateForeignKey(
+                $table, $master_field, $foreign_db, $foreign_table, $foreign_field,
+                $_REQUEST['constraint_name'][$master_field_md5],
+                $options_array[$_REQUEST['on_delete'][$master_field_md5]],
+                $options_array[$_REQUEST['on_update'][$master_field_md5]]
+            );
+
+            $display_query .= $create_query . "\n";
+            PMA_DBI_try_query($create_query);
+            $tmp_error_create = PMA_DBI_getError();
+            if (! empty($tmp_error_create)) {
+                $seen_error = true;
+
+                if (substr($tmp_error_create, 1, 4) == '1005') {
+                    $message = PMA_Message::error(
+                        __('Error creating foreign key on %1$s (check data types)')
+                    );
+                    $message->addParam($master_field);
+                    $message->display();
+                } else {
+                    $html_output .= PMA_Util::mysqlDie(
+                        $tmp_error_create, $create_query, false, '', false
+                    );
+                }
+                $html_output .= PMA_Util::showMySQLDocu(
+                    'manual_Table_types', 'InnoDB_foreign_key_constraints'
+                ) . "\n";
+            }
+
+            // this is an alteration and the old constraint has been dropped
+            // without creation of a new one
+            if ($drop && $create && empty($tmp_error_drop)
+                && ! empty($tmp_error_create)
+            ) {
+                // a rollback may be better here
+                $sql_query_recreate = '# Restoring the dropped constraint...' . "\n";
+                $sql_query_recreate .= PMA_getSQLToCreateForeignKey(
+                    $table, $master_field,
+                    PMA_Util::backquote($existrel_foreign[$master_field]['foreign_db']),
+                    PMA_Util::backquote($existrel_foreign[$master_field]['foreign_table']),
+                    PMA_Util::backquote($existrel_foreign[$master_field]['foreign_field']),
+                    $existrel_foreign[$master_field]['constraint'],
+                    $options_array[$existrel_foreign[$master_field]['on_delete']],
+                    $options_array[$existrel_foreign[$master_field]['on_update']]
+                );
+                $display_query .= $sql_query_recreate . "\n";
+                PMA_DBI_try_query($sql_query_recreate);
+            }
+        }
+    } // end foreach
+    if (! empty($display_query) && ! $seen_error) {
+        $html_output .= PMA_Util::getMessage(
+            __('Your SQL query has been executed successfully'),
+            null, 'success'
+        );
+    }
+} // end if isset($destination_foreign)
+
+
+// U p d a t e s   f o r   d i s p l a y   f i e l d
+
+if ($cfgRelation['displaywork'] && isset($display_field)) {
+    $upd_query = false;
+    if ($disp) {
+        if ($display_field != '') {
+            $upd_query = 'UPDATE '
+                . PMA_Util::backquote($GLOBALS['cfgRelation']['db'])
+                . '.' . PMA_Util::backquote($cfgRelation['table_info'])
+                . ' SET display_field = \''
+                . PMA_Util::sqlAddSlashes($display_field) . '\''
+                . ' WHERE db_name  = \'' . PMA_Util::sqlAddSlashes($db) . '\''
+                . ' AND table_name = \'' . PMA_Util::sqlAddSlashes($table) . '\'';
+        } else {
+            $upd_query = 'DELETE FROM '
+                . PMA_Util::backquote($GLOBALS['cfgRelation']['db'])
+                . '.' . PMA_Util::backquote($cfgRelation['table_info'])
+                . ' WHERE db_name  = \'' . PMA_Util::sqlAddSlashes($db) . '\''
+                . ' AND table_name = \'' . PMA_Util::sqlAddSlashes($table) . '\'';
+        }
+    } elseif ($display_field != '') {
+        $upd_query = 'INSERT INTO '
+            . PMA_Util::backquote($GLOBALS['cfgRelation']['db'])
+            . '.' . PMA_Util::backquote($cfgRelation['table_info'])
+            . '(db_name, table_name, display_field) VALUES('
+            . '\'' . PMA_Util::sqlAddSlashes($db) . '\','
+            . '\'' . PMA_Util::sqlAddSlashes($table) . '\','
+            . '\'' . PMA_Util::sqlAddSlashes($display_field) . '\')';
+    }
+
+    if ($upd_query) {
+        PMA_queryAsControlUser($upd_query);
+    }
+} // end if
+
+// If we did an update, refresh our data
+if (isset($destination) && $cfgRelation['relwork']) {
+    $existrel = PMA_getForeigners($db, $table, '', 'internal');
+}
+if (isset($destination_foreign)
+    && PMA_Util::isForeignKeySupported($tbl_storage_engine)
+) {
+    $existrel_foreign = PMA_getForeigners($db, $table, '', 'foreign');
+}
+
+if ($cfgRelation['displaywork']) {
+    $disp     = PMA_getDisplayField($db, $table);
+}
+
+
+/**
+ * Dialog
+ */
+
+// common form
+$html_output .= '<form method="post" action="tbl_relation.php">' . "\n"
+    . PMA_generate_common_hidden_inputs($db, $table);
+
+
+// relations
+
+if ($cfgRelation['relwork']
+    || PMA_Util::isForeignKeySupported($tbl_storage_engine)
+) {
+    // To choose relations we first need all tables names in current db
+    // and if the main table supports foreign keys
+    // we use SHOW TABLE STATUS because we need to find other tables of the
+    // same engine.
+
+    if (PMA_Util::isForeignKeySupported($tbl_storage_engine)) {
+        $tab_query = 'SHOW TABLE STATUS FROM ' . PMA_Util::backquote($db);
+        // [0] of the row is the name
+        // [1] is the type
+    } else {
+        $tab_query = 'SHOW TABLES FROM ' . PMA_Util::backquote($db);
+        // [0] of the row is the name
+    }
+
+    $tab_rs = PMA_DBI_query($tab_query, null, PMA_DBI_QUERY_STORE);
+    $selectboxall[] = '';
+    $selectboxall_foreign[] = '';
+
+    while ($curr_table = PMA_DBI_fetch_row($tab_rs)) {
+        $current_table = new PMA_Table($curr_table[0], $db);
+
+        // explicitely ask for non-quoted list of indexed columns
+        $selectboxall = array_merge(
+            $selectboxall,
+            $current_table->getUniqueColumns($backquoted = false)
+        );
+
+        // if foreign keys are supported, collect all keys from other
+        // tables of the same engine
+        if (PMA_Util::isForeignKeySupported($tbl_storage_engine)
+            && isset($curr_table[1])
+            && strtoupper($curr_table[1]) == $tbl_storage_engine
+        ) {
+             // explicitely ask for non-quoted list of indexed columns
+             // need to obtain backquoted values to support dots inside values
+             $selectboxall_foreign = array_merge(
+                 $selectboxall_foreign,
+                 $current_table->getIndexedColumns($backquoted = true)
+             );
+        }
+    } // end while over tables
+} // end if
+
+// Now find out the columns of our $table
+// need to use PMA_DBI_QUERY_STORE with PMA_DBI_num_rows() in mysqli
+$columns = PMA_DBI_get_columns($db, $table);
+
+if (count($columns) > 0) {
+
+    foreach ($columns as $row) {
+        $save_row[] = $row;
+    }
+
+    $saved_row_cnt  = count($save_row);
+    $html_output .= '<fieldset>'
+        . '<legend>' . __('Relations'). '</legend>'
+        . '<table>'
+        . '<tr><th>' . __('Column') . '</th>';
+
+    if ($cfgRelation['relwork']) {
+        $html_output .= '<th>' . __('Internal relation');
+        if (PMA_Util::isForeignKeySupported($tbl_storage_engine)) {
+            $html_output .= PMA_Util::showHint(
+                __(
+                    'An internal relation is not necessary when a corresponding'
+                    . ' FOREIGN KEY relation exists.'
+                )
+            );
+        }
+        $html_output .= '</th>';
+    }
+
+    if (PMA_Util::isForeignKeySupported($tbl_storage_engine)) {
+        // this does not have to be translated, it's part of the MySQL syntax
+        $html_output .= '<th colspan="2">' . __('Foreign key constraint')
+            . ' (' . $tbl_storage_engine . ')';
+        $html_output .= '</th>';
+    }
+    $html_output .= '</tr>';
+
+    $odd_row = true;
+    for ($i = 0; $i < $saved_row_cnt; $i++) {
+        $myfield = $save_row[$i]['Field'];
+        // Use an md5 as array index to avoid having special characters
+        // in the name atttibure (see bug #1746964 )
+        $myfield_md5 = md5($myfield);
+        $myfield_html = htmlspecialchars($myfield);
+
+        $html_output .= '<tr class="' . ($odd_row ? 'odd' : 'even') . '">'
+            . '<td class="center">'
+            . '<strong>' . $myfield_html . '</strong>'
+            . '<input type="hidden" name="fields_name[' . $myfield_md5 . ']"'
+            . ' value="' . $myfield_html . '"/>'
+            . '</td>';
+        $odd_row = ! $odd_row;
+
+        if ($cfgRelation['relwork']) {
+            $html_output .= '<td><select name="destination[' . $myfield_md5 . ']">';
+            // PMA internal relations
+            if (isset($existrel[$myfield])) {
+                $foreign_field    = $existrel[$myfield]['foreign_db'] . '.'
+                         . $existrel[$myfield]['foreign_table'] . '.'
+                         . $existrel[$myfield]['foreign_field'];
+            } else {
+                $foreign_field    = false;
+            }
+            $seen_key = false;
+            foreach ($selectboxall as $value) {
+                $html_output .= '<option value="' . htmlspecialchars($value) . '"';
+                if ($foreign_field && $value == $foreign_field) {
+                    $html_output .= ' selected="selected"';
+                    $seen_key = true;
+                }
+                $html_output .= '>' . htmlspecialchars($value) . '</option>'. "\n";
+            } // end while
+
+            // if the link defined in relationtable points to a foreign field
+            // that is not a key in the foreign table, we show the link
+            // (will not be shown with an arrow)
+            if ($foreign_field && !$seen_key) {
+                $html_output .= '<option value="' . htmlspecialchars($foreign_field)
+                    . '"'
+                    . ' selected="selected">' . $foreign_field . '</option>'. "\n";
+            }
+            $html_output .= '</select>'
+                . '</td>';
+        } // end if (internal relations)
+
+        if (PMA_Util::isForeignKeySupported($tbl_storage_engine)) {
+            $html_output .= '<td>';
+            if (!empty($save_row[$i]['Key'])) {
+                $html_output .= '<span class="formelement">'
+                    . '<select name="destination_foreign[' . $myfield_md5 . ']"'
+                    . ' class="referenced_column_dropdown">';
+                if (isset($existrel_foreign[$myfield])) {
+                    // need to PMA_Util::backquote to support a dot character inside
+                    // an element
+                    $foreign_field = PMA_Util::backquote(
+                        $existrel_foreign[$myfield]['foreign_db']
+                    )
+                    . '.' . PMA_Util::backquote(
+                        $existrel_foreign[$myfield]['foreign_table']
+                    )
+                    . '.' . PMA_Util::backquote(
+                        $existrel_foreign[$myfield]['foreign_field']
+                    );
+                } else {
+                    $foreign_field    = false;
+                }
+
+                $found_foreign_field = false;
+                foreach ($selectboxall_foreign as $value) {
+                    $html_output .= '<option value="'
+                        . htmlspecialchars($value) . '"';
+                    if ($foreign_field && $value == $foreign_field) {
+                        $html_output .= ' selected="selected"';
+                        $found_foreign_field = true;
+                    }
+                    $html_output .= '>' . htmlspecialchars($value)
+                        . '</option>'. "\n";
+                } // end while
+
+                // we did not find the foreign field in the tables of current db,
+                // must be defined in another db so show it to avoid erasing it
+                if (!$found_foreign_field && $foreign_field) {
+                    $html_output .= '<option value="'
+                        . htmlspecialchars($foreign_field) . '"'
+                        . ' selected="selected"'
+                        . '>' . $foreign_field . '</option>' . "\n";
+                }
+                $html_output .= '</select>'
+                    . '</span>';
+
+                // For constraint name
+                $html_output .= '<span class="formelement">';
+                $constraint_name = isset($existrel_foreign[$myfield]['constraint'])
+                    ? $existrel_foreign[$myfield]['constraint'] : '';
+                $html_output .= __('Constraint name');
+                $html_output .= '<input type="text" name="constraint_name['
+                    . $myfield_md5 . ']"'
+                    . ' value="' . $constraint_name . '"/>';
+                $html_output .= '</span>' . "\n";
+
+                $html_output .= '<span class="formelement">';
+                // For ON DELETE and ON UPDATE, the default action
+                // is RESTRICT as per MySQL doc; however, a SHOW CREATE TABLE
+                // won't display the clause if it's set as RESTRICT.
+                $on_delete = isset($existrel_foreign[$myfield]['on_delete'])
+                    ? $existrel_foreign[$myfield]['on_delete'] : 'RESTRICT';
+                $html_output .= PMA_generateDropdown(
+                    'ON DELETE',
+                    'on_delete[' . $myfield_md5 . ']',
+                    $options_array,
+                    $on_delete
+                );
+                $html_output .= '</span>' . "\n";
+
+                $html_output .= '<span class="formelement">' . "\n";
+                $on_update = isset($existrel_foreign[$myfield]['on_update'])
+                    ? $existrel_foreign[$myfield]['on_update'] : 'RESTRICT';
+                $html_output .= PMA_generateDropdown(
+                    'ON UPDATE',
+                    'on_update[' . $myfield_md5 . ']',
+                    $options_array,
+                    $on_update
+                );
+                $html_output .= '</span>' . "\n";
+            } else {
+                $html_output .= __('No index defined! Create one below');
+            } // end if (a key exists)
+            $html_output .= '</td>';
+        } // end if (InnoDB)
+        $html_output .= '</tr>';
+    } // end for
+
+    unset( $myfield, $myfield_md5, $myfield_html);
+    $html_output .= '</table>' . "\n"
+        . '</fieldset>' . "\n";
+
+    if ($cfgRelation['displaywork']) {
+        // Get "display_field" infos
+        $disp = PMA_getDisplayField($db, $table);
+        $html_output .= '<fieldset>'
+            . '<label>' . __('Choose column to display') . ': </label>'
+            . '<select name="display_field">'
+            . '<option value="">---</option>';
+
+        foreach ($save_row AS $row) {
+            $html_output .= '<option value="'
+                . htmlspecialchars($row['Field']) . '"';
+            if (isset($disp) && $row['Field'] == $disp) {
+                $html_output .= ' selected="selected"';
+            }
+            $html_output .= '>' . htmlspecialchars($row['Field'])
+                . '</option>'. "\n";
+        } // end while
+
+        $html_output .= '</select>'
+            . '</fieldset>';
+    } // end if (displayworks)
+
+    $html_output .= '<fieldset class="tblFooters">'
+        . '<input type="submit" value="' . __('Save') . '" />'
+        . '</fieldset>'
+        . '</form>';
+} // end if (we have columns in this table)
+
+if (PMA_Util::isForeignKeySupported($tbl_storage_engine)) {
+    $html_output .= '<div id="index_div" class="ajax" >'
+        . PMA_getHtmlForDisplayIndexes();
+}
+// Render HTML output
+PMA_Response::getInstance()->addHTML($html_output);
+
+/**
+ * Generate dropdown choices
+ *
+ * @param string $dropdown_question Message to display
+ * @param string $select_name       Name of the <select> field
+ * @param array  $choices           Choices for dropdown
+ * @param string $selected_value    Selected value
+ *
+ * @return string The html code for existing value (for selected)
+ *
+ * @access public
+ */
+function PMA_generateDropdown(
+    $dropdown_question, $select_name, $choices, $selected_value
+) {
+    $html_output = htmlspecialchars($dropdown_question) . '&nbsp;&nbsp;'
+        . '<select name="' . htmlspecialchars($select_name) . '">' . "\n";
+
+    foreach ($choices as $one_value => $one_label) {
+        $html_output .= '<option value="' . htmlspecialchars($one_value) . '"';
+        if ($selected_value == $one_value) {
+            $html_output .= ' selected="selected" ';
+        }
+        $html_output .= '>' . htmlspecialchars($one_label) . '</option>' . "\n";
+    }
+    $html_output .= '</select>' . "\n";
+
+    return $html_output;
+}
+
+/**
+ * Split a string on backquote pairs
+ *
+ * @param string $text original string
+ *
+ * @return array containing the elements (and their surrounding backquotes)
+ *
+ * @access public
+ */
+function PMA_backquoteSplit($text)
+{
+    $elements = array();
+    $final_pos = strlen($text) - 1;
+    $pos = 0;
+    while ($pos <= $final_pos) {
+        $first_backquote = strpos($text, '`', $pos);
+        $second_backquote = strpos($text, '`', $first_backquote + 1);
+        // after the second one, there might be another one which means
+        // this is an escaped backquote
+        if ($second_backquote < $final_pos && '`' == $text[$second_backquote + 1]) {
+            $second_backquote = strpos($text, '`', $second_backquote + 2);
+        }
+        if (false === $first_backquote || false === $second_backquote) {
+            break;
+        }
+        $elements[] = substr(
+            $text, $first_backquote, $second_backquote - $first_backquote + 1
+        );
+        $pos = $second_backquote + 1;
+    }
+    return($elements);
+}
+
+/**
+ * Returns the DROP query for a foreign key constraint
+ *
+ * @param string $table table of the foreign key
+ * @param string $fk    foreign key name
+ *
+ * @return string DROP query for the foreign key constraint
+ */
+function PMA_getSQLToDropForeignKey($table, $fk)
+{
+    return 'ALTER TABLE ' . PMA_Util::backquote($table)
+        . ' DROP FOREIGN KEY ' . PMA_Util::backquote($fk) . ';';
+}
+
+/**
+ * Returns the SQL query for foreign key constraint creation
+ *
+ * @param string $table        table name
+ * @param string $field        field name
+ * @param string $foreignDb    back-quoted foreign database name
+ * @param string $foreignTable back-quoted foreign table name
+ * @param string $foreignField back-quoted foreign field name
+ * @param string $name         name of the constraint
+ * @param string $onDelete     on delete action
+ * @param string $onUpdate     on update action
+ *
+ * @return string SQL query for foreign key constraint creation
+ */
+function PMA_getSQLToCreateForeignKey($table, $field, $foreignDb, $foreignTable,
+    $foreignField, $name = null, $onDelete = null, $onUpdate = null
+) {
+    $sql_query  = 'ALTER TABLE ' . PMA_Util::backquote($table) . ' ADD ';
+    // if user entered a constraint name
+    if (! empty($name)) {
+        $sql_query .= ' CONSTRAINT ' . PMA_Util::backquote($name);
+    }
+
+    $sql_query .= ' FOREIGN KEY (' . PMA_Util::backquote($field) . ')'
+        . ' REFERENCES ' . $foreignDb . '.' . $foreignTable
+        . '(' . $foreignField . ')';
+
+    if (! empty($onDelete)) {
+        $sql_query .= ' ON DELETE ' . $onDelete;
+    }
+    if (! empty($onUpdate)) {
+        $sql_query .= ' ON UPDATE ' . $onUpdate;
+    }
+    $sql_query .= ';';
+
+    return $sql_query;
+}
+?>