]> git.mxchange.org Git - friendica.git/blobdiff - src/Database/DBStructure.php
The next boolean
[friendica.git] / src / Database / DBStructure.php
index 5374e11d575d988b5333a90f79d79e8e34627880..7c82b518b8f199df181d830dcab013d4a57ad001 100644 (file)
@@ -1,25 +1,33 @@
 <?php
 /**
- * @file src/Database/DBStructure.php
+ * @copyright Copyright (C) 2020, Friendica
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
  */
 
 namespace Friendica\Database;
 
 use Exception;
-use Friendica\Core\Config;
 use Friendica\Core\Hook;
-use Friendica\Core\L10n;
 use Friendica\Core\Logger;
+use Friendica\DI;
 use Friendica\Util\DateTimeFormat;
 
-require_once 'boot.php';
-require_once 'include/dba.php';
-require_once 'include/enotify.php';
-require_once 'include/text.php';
-
 /**
- * @brief This class contain functions for the database management
- *
  * This class contains functions that doesn't need to know if pdo, mysqli or whatever is used.
  */
 class DBStructure
@@ -38,21 +46,30 @@ class DBStructure
         */
        private static $definition = [];
 
-       /*
-        * Converts all tables from MyISAM to InnoDB
+       /**
+        * Converts all tables from MyISAM/InnoDB Antelope to InnoDB Barracuda
         */
        public static function convertToInnoDB()
        {
-               $r = q("SELECT `TABLE_NAME` FROM `information_schema`.`tables` WHERE `engine` = 'MyISAM' AND `table_schema` = '%s'",
-                       DBA::escape(DBA::databaseName()));
-
-               if (!DBA::isResult($r)) {
-                       echo L10n::t('There are no tables on MyISAM.') . "\n";
+               $tables = DBA::selectToArray(
+                       ['information_schema' => 'tables'],
+                       ['table_name'],
+                       ['engine' => 'MyISAM', 'table_schema' => DBA::databaseName()]
+               );
+
+               $tables = array_merge($tables, DBA::selectToArray(
+                       ['information_schema' => 'tables'],
+                       ['table_name'],
+                       ['engine' => 'InnoDB', 'ROW_FORMAT' => ['COMPACT', 'REDUNDANT'], 'table_schema' => DBA::databaseName()]
+               ));
+
+               if (!DBA::isResult($tables)) {
+                       echo DI::l10n()->t('There are no tables on MyISAM or InnoDB with the Antelope file format.') . "\n";
                        return;
                }
 
-               foreach ($r AS $table) {
-                       $sql = sprintf("ALTER TABLE `%s` engine=InnoDB;", DBA::escape($table['TABLE_NAME']));
+               foreach ($tables AS $table) {
+                       $sql = "ALTER TABLE " . DBA::quoteIdentifier($table['table_name']) . " ENGINE=InnoDB ROW_FORMAT=DYNAMIC;";
                        echo $sql . "\n";
 
                        $result = DBA::e($sql);
@@ -63,7 +80,7 @@ class DBStructure
        }
 
        /**
-        * @brief Print out database error messages
+        * Print out database error messages
         *
         * @param string $message Message to be added to the error message
         *
@@ -71,15 +88,15 @@ class DBStructure
         */
        private static function printUpdateError($message)
        {
-               echo L10n::t("\nError %d occurred during database update:\n%s\n",
+               echo DI::l10n()->t("\nError %d occurred during database update:\n%s\n",
                        DBA::errorNo(), DBA::errorMessage());
 
-               return L10n::t('Errors encountered performing database changes: ') . $message . EOL;
+               return DI::l10n()->t('Errors encountered performing database changes: ') . $message . EOL;
        }
 
-       public static function printStructure()
+       public static function printStructure($basePath)
        {
-               $database = self::definition(false);
+               $database = self::definition($basePath, false);
 
                echo "-- ------------------------------------------\n";
                echo "-- " . FRIENDICA_PLATFORM . " " . FRIENDICA_VERSION . " (" . FRIENDICA_CODENAME, ")\n";
@@ -93,32 +110,34 @@ class DBStructure
 
                        echo "\n";
                }
+
+               View::printStructure($basePath);
        }
 
        /**
-        * Loads the database structure definition from the config/dbstructure.config.php file.
+        * Loads the database structure definition from the static/dbstructure.config.php file.
         * On first pass, defines DB_UPDATE_VERSION constant.
         *
-        * @see config/dbstructure.config.php
+        * @see static/dbstructure.config.php
         * @param boolean $with_addons_structure Whether to tack on addons additional tables
+        * @param string  $basePath              The base path of this application
         * @return array
         * @throws Exception
         */
-       public static function definition($with_addons_structure = true)
+       public static function definition($basePath, $with_addons_structure = true)
        {
                if (!self::$definition) {
-                       $a = \Friendica\BaseObject::getApp();
 
-                       $filename = $a->getBasePath() . '/config/dbstructure.config.php';
+                       $filename = $basePath . '/static/dbstructure.config.php';
 
                        if (!is_readable($filename)) {
-                               throw new Exception('Missing database structure config file config/dbstructure.config.php');
+                               throw new Exception('Missing database structure config file static/dbstructure.config.php');
                        }
 
                        $definition = require $filename;
 
                        if (!$definition) {
-                               throw new Exception('Corrupted database structure config file config/dbstructure.config.php');
+                               throw new Exception('Corrupted database structure config file static/dbstructure.config.php');
                        }
 
                        self::$definition = $definition;
@@ -141,11 +160,16 @@ class DBStructure
                $comment = "";
                $sql_rows = [];
                $primary_keys = [];
+               $foreign_keys = [];
+
                foreach ($structure["fields"] AS $fieldname => $field) {
                        $sql_rows[] = "`" . DBA::escape($fieldname) . "` " . self::FieldCommand($field);
                        if (!empty($field['primary'])) {
                                $primary_keys[] = $fieldname;
                        }
+                       if (!empty($field['foreign'])) {
+                               $foreign_keys[$fieldname] = $field;
+                       }
                }
 
                if (!empty($structure["indexes"])) {
@@ -157,6 +181,10 @@ class DBStructure
                        }
                }
 
+               foreach ($foreign_keys AS $fieldname => $parameters) {
+                       $sql_rows[] = self::foreignCommand($name, $fieldname, $parameters);
+               }
+
                if (isset($structure["engine"])) {
                        $engine = " ENGINE=" . $structure["engine"];
                }
@@ -220,9 +248,9 @@ class DBStructure
                        throw new Exception("Invalid parameter 'method' in self::createIndex(): '$method'");
                }
 
-               if ($fieldnames[0] == "UNIQUE") {
-                       array_shift($fieldnames);
-                       $method .= ' UNIQUE';
+               if (in_array($fieldnames[0], ["UNIQUE", "FULLTEXT"])) {
+                       $index_type = array_shift($fieldnames);
+                       $method .= " " . $index_type;
                }
 
                $names = "";
@@ -250,18 +278,20 @@ class DBStructure
        /**
         * Updates DB structure and returns eventual errors messages
         *
-        * @param bool  $verbose
-        * @param bool  $action     Whether to actually apply the update
-        * @param bool  $install    Is this the initial update during the installation?
-        * @param array $tables     An array of the database tables
-        * @param array $definition An array of the definition tables
+        * @param string $basePath   The base path of this application
+        * @param bool   $verbose
+        * @param bool   $action     Whether to actually apply the update
+        * @param bool   $install    Is this the initial update during the installation?
+        * @param array  $tables     An array of the database tables
+        * @param array  $definition An array of the definition tables
         * @return string Empty string if the update is successful, error messages otherwise
+        * @throws Exception
         */
-       public static function update($verbose, $action, $install = false, array $tables = null, array $definition = null)
+       public static function update($basePath, $verbose, $action, $install = false, array $tables = null, array $definition = null)
        {
                if ($action && !$install) {
-                       Config::set('system', 'maintenance', 1);
-                       Config::set('system', 'maintenance_reason', L10n::t('%s: Database update', DateTimeFormat::utcNow() . ' ' . date('e')));
+                       DI::config()->set('system', 'maintenance', 1);
+                       DI::config()->set('system', 'maintenance_reason', DI::l10n()->t('%s: Database update', DateTimeFormat::utcNow() . ' ' . date('e')));
                }
 
                $errors = '';
@@ -272,7 +302,7 @@ class DBStructure
                $database = [];
 
                if (is_null($tables)) {
-                       $tables = q("SHOW TABLES");
+                       $tables = DBA::toArray(DBA::p("SHOW TABLES"));
                }
 
                if (DBA::isResult($tables)) {
@@ -286,7 +316,7 @@ class DBStructure
 
                // Get the definition
                if (is_null($definition)) {
-                       $definition = self::definition();
+                       $definition = self::definition($basePath);
                }
 
                // MySQL >= 5.7.4 doesn't support the IGNORE keyword in ALTER TABLE statements
@@ -364,6 +394,7 @@ class DBStructure
 
                                                // Remove the relation data that is used for the referential integrity
                                                unset($parameters['relation']);
+                                               unset($parameters['foreign']);
 
                                                // We change the collation after the indexes had been changed.
                                                // This is done to avoid index length problems.
@@ -407,9 +438,7 @@ class DBStructure
                                                $sql2 = self::createIndex($indexname, $fieldnames);
 
                                                // Fetch the "group by" fields for unique indexes
-                                               if ($fieldnames[0] == "UNIQUE") {
-                                                       $group_by = self::groupBy($indexname, $fieldnames);
-                                               }
+                                               $group_by = self::groupBy($fieldnames);
                                                if ($sql2 != "") {
                                                        if ($sql3 == "") {
                                                                $sql3 = "ALTER" . $ignore . " TABLE `" . $temp_name . "` " . $sql2;
@@ -420,9 +449,43 @@ class DBStructure
                                        }
                                }
 
-                               if (isset($database[$name]["table_status"]["Comment"])) {
-                                       $structurecomment = defaults($structure, "comment", "");
-                                       if ($database[$name]["table_status"]["Comment"] != $structurecomment) {
+                               $existing_foreign_keys = $database[$name]['foreign_keys'];
+
+                               // Foreign keys
+                               // Compare the field structure field by field
+                               foreach ($structure["fields"] AS $fieldname => $parameters) {
+                                       if (empty($parameters['foreign'])) {
+                                               continue;
+                                       }
+
+                                       $constraint = self::getConstraintName($name, $fieldname, $parameters);
+
+                                       unset($existing_foreign_keys[$constraint]);
+
+                                       if (empty($database[$name]['foreign_keys'][$constraint])) {
+                                               $sql2 = self::addForeignKey($name, $fieldname, $parameters);
+
+                                               if ($sql3 == "") {
+                                                       $sql3 = "ALTER" . $ignore . " TABLE `" . $temp_name . "` " . $sql2;
+                                               } else {
+                                                       $sql3 .= ", " . $sql2;
+                                               }
+                                       }
+                               }
+
+                               foreach ($existing_foreign_keys as $constraint => $param) {
+                                       $sql2 = self::dropForeignKey($constraint);
+
+                                       if ($sql3 == "") {
+                                               $sql3 = "ALTER" . $ignore . " TABLE `" . $temp_name . "` " . $sql2;
+                                       } else {
+                                               $sql3 .= ", " . $sql2;
+                                       }
+                               }
+
+                               if (isset($database[$name]["table_status"]["TABLE_COMMENT"])) {
+                                       $structurecomment = $structure["comment"] ?? '';
+                                       if ($database[$name]["table_status"]["TABLE_COMMENT"] != $structurecomment) {
                                                $sql2 = "COMMENT = '" . DBA::escape($structurecomment) . "'";
 
                                                if ($sql3 == "") {
@@ -433,8 +496,8 @@ class DBStructure
                                        }
                                }
 
-                               if (isset($database[$name]["table_status"]["Engine"]) && isset($structure['engine'])) {
-                                       if ($database[$name]["table_status"]["Engine"] != $structure['engine']) {
+                               if (isset($database[$name]["table_status"]["ENGINE"]) && isset($structure['engine'])) {
+                                       if ($database[$name]["table_status"]["ENGINE"] != $structure['engine']) {
                                                $sql2 = "ENGINE = '" . DBA::escape($structure['engine']) . "'";
 
                                                if ($sql3 == "") {
@@ -445,8 +508,8 @@ class DBStructure
                                        }
                                }
 
-                               if (isset($database[$name]["table_status"]["Collation"])) {
-                                       if ($database[$name]["table_status"]["Collation"] != 'utf8mb4_general_ci') {
+                               if (isset($database[$name]["table_status"]["TABLE_COLLATION"])) {
+                                       if ($database[$name]["table_status"]["TABLE_COLLATION"] != 'utf8mb4_general_ci') {
                                                $sql2 = "DEFAULT COLLATE utf8mb4_general_ci";
 
                                                if ($sql3 == "") {
@@ -465,7 +528,7 @@ class DBStructure
                                // Compare the field structure field by field
                                foreach ($structure["fields"] AS $fieldname => $parameters) {
                                        // Compare the field definition
-                                       $field_definition = defaults($database[$name]["fields"], $fieldname, ['Collation' => '']);
+                                       $field_definition = ($database[$name]["fields"][$fieldname] ?? '') ?: ['Collation' => ''];
 
                                        // Define the default collation if not given
                                        if (!isset($parameters['Collation']) && !empty($field_definition['Collation'])) {
@@ -524,7 +587,7 @@ class DBStructure
 
                                if ($action) {
                                        if (!$install) {
-                                               Config::set('system', 'maintenance_reason', L10n::t('%s: updating %s table.', DateTimeFormat::utcNow() . ' ' . date('e'), $name));
+                                               DI::config()->set('system', 'maintenance_reason', DI::l10n()->t('%s: updating %s table.', DateTimeFormat::utcNow() . ' ' . date('e'), $name));
                                        }
 
                                        // Ensure index conversion to unique removes duplicates
@@ -575,14 +638,16 @@ class DBStructure
                        }
                }
 
+               View::create(false, $action);
+
                if ($action && !$install) {
-                       Config::set('system', 'maintenance', 0);
-                       Config::set('system', 'maintenance_reason', '');
+                       DI::config()->set('system', 'maintenance', 0);
+                       DI::config()->set('system', 'maintenance_reason', '');
 
                        if ($errors) {
-                               Config::set('system', 'dbupdate', self::UPDATE_FAILED);
+                               DI::config()->set('system', 'dbupdate', self::UPDATE_FAILED);
                        } else {
-                               Config::set('system', 'dbupdate', self::UPDATE_SUCCESSFUL);
+                               DI::config()->set('system', 'dbupdate', self::UPDATE_SUCCESSFUL);
                        }
                }
 
@@ -591,27 +656,45 @@ class DBStructure
 
        private static function tableStructure($table)
        {
-               $structures = q("DESCRIBE `%s`", $table);
+               // This query doesn't seem to be executable as a prepared statement
+               $indexes = DBA::toArray(DBA::p("SHOW INDEX FROM " . DBA::quoteIdentifier($table)));
 
-               $full_columns = q("SHOW FULL COLUMNS FROM `%s`", $table);
+               $fields = DBA::selectToArray(['INFORMATION_SCHEMA' => 'COLUMNS'],
+                       ['COLUMN_NAME', 'COLUMN_TYPE', 'IS_NULLABLE', 'COLUMN_DEFAULT', 'EXTRA',
+                       'COLUMN_KEY', 'COLLATION_NAME', 'COLUMN_COMMENT'],
+                       ["`TABLE_SCHEMA` = ? AND `TABLE_NAME` = ?",
+                       DBA::databaseName(), $table]);
 
-               $indexes = q("SHOW INDEX FROM `%s`", $table);
+               $foreign_keys = DBA::selectToArray(['INFORMATION_SCHEMA' => 'KEY_COLUMN_USAGE'],
+                       ['COLUMN_NAME', 'CONSTRAINT_NAME', 'REFERENCED_TABLE_NAME', 'REFERENCED_COLUMN_NAME'],
+                       ["`TABLE_SCHEMA` = ? AND `TABLE_NAME` = ? AND `REFERENCED_TABLE_SCHEMA` IS NOT NULL",
+                       DBA::databaseName(), $table]);
 
-               $table_status = q("SHOW TABLE STATUS WHERE `name` = '%s'", $table);
-
-               if (DBA::isResult($table_status)) {
-                       $table_status = $table_status[0];
-               } else {
-                       $table_status = [];
-               }
+               $table_status = DBA::selectFirst(['INFORMATION_SCHEMA' => 'TABLES'],
+                       ['ENGINE', 'TABLE_COLLATION', 'TABLE_COMMENT'],
+                       ["`TABLE_SCHEMA` = ? AND `TABLE_NAME` = ?",
+                       DBA::databaseName(), $table]);
 
                $fielddata = [];
                $indexdata = [];
+               $foreigndata = [];
+
+               if (DBA::isResult($foreign_keys)) {
+                       foreach ($foreign_keys as $foreign_key) {
+                               $constraint = $foreign_key['CONSTRAINT_NAME'];
+                               unset($foreign_key['CONSTRAINT_NAME']); 
+                               $foreigndata[$constraint] = $foreign_key;
+                       }
+               }
 
                if (DBA::isResult($indexes)) {
                        foreach ($indexes AS $index) {
-                               if ($index['Key_name'] != 'PRIMARY' && $index['Non_unique'] == '0' && !isset($indexdata[$index["Key_name"]])) {
-                                       $indexdata[$index["Key_name"]] = ['UNIQUE'];
+                               if ($index["Key_name"] != "PRIMARY" && $index["Non_unique"] == "0" && !isset($indexdata[$index["Key_name"]])) {
+                                       $indexdata[$index["Key_name"]] = ["UNIQUE"];
+                               }
+
+                               if ($index["Index_type"] == "FULLTEXT" && !isset($indexdata[$index["Key_name"]])) {
+                                       $indexdata[$index["Key_name"]] = ["FULLTEXT"];
                                }
 
                                $column = $index["Column_name"];
@@ -623,39 +706,39 @@ class DBStructure
                                $indexdata[$index["Key_name"]][] = $column;
                        }
                }
-               if (DBA::isResult($structures)) {
-                       foreach ($structures AS $field) {
-                               // Replace the default size values so that we don't have to define them
+
+               $fielddata = [];
+               if (DBA::isResult($fields)) {
+                       foreach ($fields AS $field) {
                                $search = ['tinyint(1)', 'tinyint(3) unsigned', 'tinyint(4)', 'smallint(5) unsigned', 'smallint(6)', 'mediumint(8) unsigned', 'mediumint(9)', 'bigint(20)', 'int(10) unsigned', 'int(11)'];
                                $replace = ['boolean', 'tinyint unsigned', 'tinyint', 'smallint unsigned', 'smallint', 'mediumint unsigned', 'mediumint', 'bigint', 'int unsigned', 'int'];
-                               $field["Type"] = str_replace($search, $replace, $field["Type"]);
+                               $field['COLUMN_TYPE'] = str_replace($search, $replace, $field['COLUMN_TYPE']);
+
+                               $fielddata[$field['COLUMN_NAME']]['type'] = $field['COLUMN_TYPE'];
 
-                               $fielddata[$field["Field"]]["type"] = $field["Type"];
-                               if ($field["Null"] == "NO") {
-                                       $fielddata[$field["Field"]]["not null"] = true;
+                               if ($field['IS_NULLABLE'] == 'NO') {
+                                       $fielddata[$field['COLUMN_NAME']]['not null'] = true;
                                }
 
-                               if (isset($field["Default"])) {
-                                       $fielddata[$field["Field"]]["default"] = $field["Default"];
+                               if (isset($field['COLUMN_DEFAULT'])) {
+                                       $fielddata[$field['COLUMN_NAME']]['default'] = $field['COLUMN_DEFAULT'];
                                }
 
-                               if ($field["Extra"] != "") {
-                                       $fielddata[$field["Field"]]["extra"] = $field["Extra"];
+                               if (!empty($field['EXTRA'])) {
+                                       $fielddata[$field['COLUMN_NAME']]['extra'] = $field['EXTRA'];
                                }
 
-                               if ($field["Key"] == "PRI") {
-                                       $fielddata[$field["Field"]]["primary"] = true;
+                               if ($field['COLUMN_KEY'] == 'PRI') {
+                                       $fielddata[$field['COLUMN_NAME']]['primary'] = true;
                                }
-                       }
-               }
-               if (DBA::isResult($full_columns)) {
-                       foreach ($full_columns AS $column) {
-                               $fielddata[$column["Field"]]["Collation"] = $column["Collation"];
-                               $fielddata[$column["Field"]]["comment"] = $column["Comment"];
+
+                               $fielddata[$field['COLUMN_NAME']]['Collation'] = $field['COLLATION_NAME'];
+                               $fielddata[$field['COLUMN_NAME']]['comment'] = $field['COLUMN_COMMENT'];
                        }
                }
 
-               return ["fields" => $fielddata, "indexes" => $indexdata, "table_status" => $table_status];
+               return ["fields" => $fielddata, "indexes" => $indexdata,
+                       "foreign_keys" => $foreigndata, "table_status" => $table_status];
        }
 
        private static function dropIndex($indexname)
@@ -676,7 +759,55 @@ class DBStructure
                return ($sql);
        }
 
-       private static function groupBy($indexname, $fieldnames)
+       private static function getConstraintName(string $tablename, string $fieldname, array $parameters)
+       {
+               $foreign_table = array_keys($parameters['foreign'])[0];
+               $foreign_field = array_values($parameters['foreign'])[0];
+
+               return $tablename . "-" . $fieldname. "-" . $foreign_table. "-" . $foreign_field;
+       }
+
+       private static function foreignCommand(string $tablename, string $fieldname, array $parameters) {
+               $foreign_table = array_keys($parameters['foreign'])[0];
+               $foreign_field = array_values($parameters['foreign'])[0];
+
+               $constraint = self::getConstraintName($tablename, $fieldname, $parameters);
+
+               $sql = "CONSTRAINT `" . $constraint . "` FOREIGN KEY (`" . $fieldname . "`)" .
+                       " REFERENCES `" . $foreign_table . "` (`" . $foreign_field . "`)";
+
+               if (!empty($parameters['foreign']['on update'])) {
+                       $sql .= " ON UPDATE " . strtoupper($parameters['foreign']['on update']);
+               } else {
+                       $sql .= " ON UPDATE RESTRICT";
+               }
+
+               if (!empty($parameters['foreign']['on delete'])) {
+                       $sql .= " ON DELETE " . strtoupper($parameters['foreign']['on delete']);
+               } else {
+                       $sql .= " ON DELETE CASCADE";
+               }
+
+               return $sql;
+       }
+
+       private static function addForeignKey(string $tablename, string $fieldname, array $parameters)
+       {
+               return sprintf("ADD %s", self::foreignCommand($tablename, $fieldname, $parameters));
+       }
+
+       private static function dropForeignKey(string $constraint)
+       {
+               return sprintf("DROP FOREIGN KEY `%s`", $constraint);
+       }
+
+       /**
+        * Constructs a GROUP BY clause from a UNIQUE index definition.
+        *
+        * @param array $fieldnames
+        * @return string
+        */
+       private static function groupBy(array $fieldnames)
        {
                if ($fieldnames[0] != "UNIQUE") {
                        return "";
@@ -707,12 +838,12 @@ class DBStructure
         * @todo You cannot rename a primary key if "auto increment" is set
         *
         * @param string $table            Table name
-        * @param array  $columns          Columns Syntax for Rename: [ $old1 => [ $new1, $type1 ], $old2 => [ $new2, $type2 ], ... ] )
-        *                                 Syntax for Primary Key: [ $col1, $col2, ...] )
+        * @param array  $columns          Columns Syntax for Rename: [ $old1 => [ $new1, $type1 ], $old2 => [ $new2, $type2 ], ... ]
+        *                                 Syntax for Primary Key: [ $col1, $col2, ...]
         * @param int    $type             The type of renaming (Default is Column)
         *
         * @return boolean Was the renaming successful?
-        *
+        * @throws Exception
         */
        public static function rename($table, $columns, $type = self::RENAME_COLUMN)
        {
@@ -772,6 +903,7 @@ class DBStructure
         * @param array  $columns Columns to check ( Syntax: [ $col1, $col2, .. ] )
         *
         * @return boolean Does the table exist?
+        * @throws Exception
         */
        public static function existsColumn($table, $columns = [])
        {
@@ -809,9 +941,10 @@ class DBStructure
        /**
         *    Check if a table exists
         *
-        * @param string $table Table name
+        * @param string|array $table Table name
         *
         * @return boolean Does the table exist?
+        * @throws Exception
         */
        public static function existsTable($table)
        {
@@ -819,20 +952,28 @@ class DBStructure
                        return false;
                }
 
-               $table = DBA::escape($table);
-
-               $sql = "SHOW TABLES LIKE '" . $table . "';";
-
-               $stmt = DBA::p($sql);
-
-               if (is_bool($stmt)) {
-                       $retval = $stmt;
+               if (is_array($table)) {
+                       $condition = ['table_schema' => key($table), 'table_name' => current($table)];
                } else {
-                       $retval = (DBA::numRows($stmt) > 0);
+                       $condition = ['table_schema' => DBA::databaseName(), 'table_name' => $table];
                }
 
-               DBA::close($stmt);
+               $result = DBA::exists(['information_schema' => 'tables'], $condition);
 
-               return $retval;
+               return $result;
+       }
+
+       /**
+        * Returns the columns of a table
+        *
+        * @param string $table Table name
+        *
+        * @return array An array of the table columns
+        * @throws Exception
+        */
+       public static function getColumns($table)
+       {
+               $stmtColumns = DBA::p("SHOW COLUMNS FROM `" . $table . "`");
+               return DBA::toArray($stmtColumns);
        }
 }