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<?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/>./*** PostgreSQL specific SQL code generator.** @package core_ddl* @copyright 1999 onwards Martin Dougiamas http://dougiamas.com* 2001-3001 Eloy Lafuente (stronk7) http://contiento.com* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later*/defined('MOODLE_INTERNAL') || die();require_once($CFG->libdir.'/ddl/sql_generator.php');/*** This class generate SQL code to be used against PostgreSQL* It extends XMLDBgenerator so everything can be* overridden as needed to generate correct SQL.** @package core_ddl* @copyright 1999 onwards Martin Dougiamas http://dougiamas.com* 2001-3001 Eloy Lafuente (stronk7) http://contiento.com* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later*/class postgres_sql_generator extends sql_generator {// Only set values that are different from the defaults present in XMLDBgenerator/** @var string Proper type for NUMBER(x) in this DB. */public $number_type = 'NUMERIC';/** @var string To define the default to set for NOT NULLs CHARs without default (null=do nothing).*/public $default_for_char = '';/** @var bool True if the generator needs to add extra code to generate the sequence fields.*/public $sequence_extra_code = false;/** @var string The particular name for inline sequences in this generator.*/public $sequence_name = 'BIGSERIAL';/** @var string The particular name for inline sequences in this generator.*/public $sequence_name_small = 'SERIAL';/** @var bool To avoid outputting the rest of the field specs, leaving only the name and the sequence_name returned.*/public $sequence_only = true;/** @var string SQL sentence to rename one index where 'TABLENAME', 'OLDINDEXNAME' and 'NEWINDEXNAME' are dynamically replaced.*/public $rename_index_sql = 'ALTER TABLE OLDINDEXNAME RENAME TO NEWINDEXNAME';/** @var string SQL sentence to rename one key 'TABLENAME', 'OLDKEYNAME' and 'NEWKEYNAME' are dynamically replaced.*/public $rename_key_sql = null;/** @var string type of string quoting used - '' or \' quotes*/protected $std_strings = null;/*** Reset a sequence to the id field of a table.** @param xmldb_table|string $table name of table or the table object.* @return array of sql statements*/public function getResetSequenceSQL($table) {if ($table instanceof xmldb_table) {$tablename = $table->getName();} else {$tablename = $table;}// From http://www.postgresql.org/docs/7.4/static/sql-altersequence.html$value = (int)$this->mdb->get_field_sql('SELECT MAX(id) FROM {'.$tablename.'}');$value++;return array("ALTER SEQUENCE $this->prefix{$tablename}_id_seq RESTART WITH $value");}/*** Given one correct xmldb_table, returns the SQL statements* to create temporary table (inside one array).** @param xmldb_table $xmldb_table The xmldb_table object instance.* @return array of sql statements*/public function getCreateTempTableSQL($xmldb_table) {$this->temptables->add_temptable($xmldb_table->getName());$sqlarr = $this->getCreateTableSQL($xmldb_table);$sqlarr = preg_replace('/^CREATE TABLE/', "CREATE TEMPORARY TABLE", $sqlarr);return $sqlarr;}/*** Given one correct xmldb_index, returns the SQL statements* needed to create it (in array).** @param xmldb_table $xmldb_table The xmldb_table instance to create the index on.* @param xmldb_index $xmldb_index The xmldb_index to create.* @return array An array of SQL statements to create the index.* @throws coding_exception Thrown if the xmldb_index does not validate with the xmldb_table.*/public function getCreateIndexSQL($xmldb_table, $xmldb_index) {$sqls = parent::getCreateIndexSQL($xmldb_table, $xmldb_index);$hints = $xmldb_index->getHints();$fields = $xmldb_index->getFields();if (in_array('varchar_pattern_ops', $hints) and count($fields) == 1) {// Add the pattern index and keep the normal one, keep unique only the standard index to improve perf.foreach ($sqls as $sql) {$field = reset($fields);$count = 0;$newindex = preg_replace("/^CREATE( UNIQUE)? INDEX ([a-z0-9_]+) ON ([a-z0-9_]+) \($field\)$/", "CREATE INDEX \\2_pattern ON \\3 USING btree ($field varchar_pattern_ops)", $sql, -1, $count);if ($count != 1) {debugging('Unexpected getCreateIndexSQL() structure.');continue;}$sqls[] = $newindex;}}return $sqls;}/*** Given one XMLDB Type, length and decimals, returns the DB proper SQL type.** @param int $xmldb_type The xmldb_type defined constant. XMLDB_TYPE_INTEGER and other XMLDB_TYPE_* constants.* @param int $xmldb_length The length of that data type.* @param int $xmldb_decimals The decimal places of precision of the data type.* @return string The DB defined data type.*/public function getTypeSQL($xmldb_type, $xmldb_length=null, $xmldb_decimals=null) {switch ($xmldb_type) {case XMLDB_TYPE_INTEGER: // From http://www.postgresql.org/docs/7.4/interactive/datatype.htmlif (empty($xmldb_length)) {$xmldb_length = 10;}if ($xmldb_length > 9) {$dbtype = 'BIGINT';} else if ($xmldb_length > 4) {$dbtype = 'INTEGER';} else {$dbtype = 'SMALLINT';}break;case XMLDB_TYPE_NUMBER:$dbtype = $this->number_type;if (!empty($xmldb_length)) {$dbtype .= '(' . $xmldb_length;if (!empty($xmldb_decimals)) {$dbtype .= ',' . $xmldb_decimals;}$dbtype .= ')';}break;case XMLDB_TYPE_FLOAT:$dbtype = 'DOUBLE PRECISION';if (!empty($xmldb_decimals)) {if ($xmldb_decimals < 6) {$dbtype = 'REAL';}}break;case XMLDB_TYPE_CHAR:$dbtype = 'VARCHAR';if (empty($xmldb_length)) {$xmldb_length='255';}$dbtype .= '(' . $xmldb_length . ')';break;case XMLDB_TYPE_TEXT:$dbtype = 'TEXT';break;case XMLDB_TYPE_BINARY:$dbtype = 'BYTEA';break;case XMLDB_TYPE_DATETIME:$dbtype = 'TIMESTAMP';break;}return $dbtype;}/*** Returns the code (array of statements) needed to add one comment to the table.** @param xmldb_table $xmldb_table The xmldb_table object instance.* @return array Array of SQL statements to add one comment to the table.*/function getCommentSQL($xmldb_table) {$comment = "COMMENT ON TABLE " . $this->getTableName($xmldb_table);$comment.= " IS '" . $this->addslashes(substr($xmldb_table->getComment(), 0, 250)) . "'";return array($comment);}/*** Returns the code (array of statements) needed to execute extra statements on table rename.** @param xmldb_table $xmldb_table The xmldb_table object instance.* @param string $newname The new name for the table.* @return array Array of extra SQL statements to rename a table.*/public function getRenameTableExtraSQL($xmldb_table, $newname) {$results = array();$newt = new xmldb_table($newname);$xmldb_field = new xmldb_field('id'); // Fields having sequences should be exclusively, id.$oldseqname = $this->getTableName($xmldb_table) . '_' . $xmldb_field->getName() . '_seq';$newseqname = $this->getTableName($newt) . '_' . $xmldb_field->getName() . '_seq';// Rename de sequence$results[] = 'ALTER TABLE ' . $oldseqname . ' RENAME TO ' . $newseqname;return $results;}/*** Given one xmldb_table and one xmldb_field, return the SQL statements needed to alter the field in the table.** PostgreSQL has some severe limits:* - Any change of type or precision requires a new temporary column to be created, values to* be transfered potentially casting them, to apply defaults if the column is not null and* finally, to rename it* - Changes in null/not null require the SET/DROP NOT NULL clause* - Changes in default require the SET/DROP DEFAULT clause** @param xmldb_table $xmldb_table The table related to $xmldb_field.* @param xmldb_field $xmldb_field The instance of xmldb_field to create the SQL from.* @param string $skip_type_clause The type clause on alter columns, NULL by default.* @param string $skip_default_clause The default clause on alter columns, NULL by default.* @param string $skip_notnull_clause The null/notnull clause on alter columns, NULL by default.* @return string The field altering SQL statement.*/public function getAlterFieldSQL($xmldb_table, $xmldb_field, $skip_type_clause = NULL, $skip_default_clause = NULL, $skip_notnull_clause = NULL) {$results = array(); // To store all the needed SQL commands// Get the normal names of the table and field$tablename = $xmldb_table->getName();$fieldname = $xmldb_field->getName();// Take a look to field metadata$meta = $this->mdb->get_columns($tablename);$metac = $meta[$xmldb_field->getName()];$oldmetatype = $metac->meta_type;$oldlength = $metac->max_length;$olddecimals = empty($metac->scale) ? null : $metac->scale;$oldnotnull = empty($metac->not_null) ? false : $metac->not_null;$olddefault = empty($metac->has_default) ? null : $metac->default_value;$typechanged = true; //By default, assume that the column type has changed$precisionchanged = true; //By default, assume that the column precision has changed$decimalchanged = true; //By default, assume that the column decimal has changed$defaultchanged = true; //By default, assume that the column default has changed$notnullchanged = true; //By default, assume that the column notnull has changed// Detect if we are changing the type of the columnif (($xmldb_field->getType() == XMLDB_TYPE_INTEGER && $oldmetatype == 'I') ||($xmldb_field->getType() == XMLDB_TYPE_NUMBER && $oldmetatype == 'N') ||($xmldb_field->getType() == XMLDB_TYPE_FLOAT && $oldmetatype == 'F') ||($xmldb_field->getType() == XMLDB_TYPE_CHAR && $oldmetatype == 'C') ||($xmldb_field->getType() == XMLDB_TYPE_TEXT && $oldmetatype == 'X') ||($xmldb_field->getType() == XMLDB_TYPE_BINARY && $oldmetatype == 'B')) {$typechanged = false;}// Detect if we are changing the precisionif (($xmldb_field->getType() == XMLDB_TYPE_TEXT) ||($xmldb_field->getType() == XMLDB_TYPE_BINARY) ||($oldlength == -1) ||($xmldb_field->getLength() == $oldlength)) {$precisionchanged = false;}// Detect if we are changing the decimalsif (($xmldb_field->getType() == XMLDB_TYPE_INTEGER) ||($xmldb_field->getType() == XMLDB_TYPE_CHAR) ||($xmldb_field->getType() == XMLDB_TYPE_TEXT) ||($xmldb_field->getType() == XMLDB_TYPE_BINARY) ||(!$xmldb_field->getDecimals()) ||(!$olddecimals) ||($xmldb_field->getDecimals() == $olddecimals)) {$decimalchanged = false;}// Detect if we are changing the defaultif (($xmldb_field->getDefault() === null && $olddefault === null) ||($xmldb_field->getDefault() === $olddefault)) {$defaultchanged = false;}// Detect if we are changing the nullabilityif (($xmldb_field->getNotnull() === $oldnotnull)) {$notnullchanged = false;}// Get the quoted name of the table and field$tablename = $this->getTableName($xmldb_table);$fieldname = $this->getEncQuoted($xmldb_field->getName());// Decide if we have changed the column specs (type/precision/decimals)$specschanged = $typechanged || $precisionchanged || $decimalchanged;// if specs have changed, need to alter columnif ($specschanged) {// Always drop any exiting default before alter column (some type changes can cause casting error in default for column)if ($olddefault !== null) {$results[] = 'ALTER TABLE ' . $tablename . ' ALTER COLUMN ' . $fieldname . ' DROP DEFAULT'; // Drop default clause}$alterstmt = 'ALTER TABLE ' . $tablename . ' ALTER COLUMN ' . $this->getEncQuoted($xmldb_field->getName()) .' TYPE' . $this->getFieldSQL($xmldb_table, $xmldb_field, null, true, true, null, false);// Some castings must be performed explicitly (mainly from text|char to numeric|integer)if (($oldmetatype == 'C' || $oldmetatype == 'X') &&($xmldb_field->getType() == XMLDB_TYPE_NUMBER || $xmldb_field->getType() == XMLDB_TYPE_FLOAT)) {$alterstmt .= ' USING CAST('.$fieldname.' AS NUMERIC)'; // from char or text to number or float} else if (($oldmetatype == 'C' || $oldmetatype == 'X') &&$xmldb_field->getType() == XMLDB_TYPE_INTEGER) {$alterstmt .= ' USING CAST(CAST('.$fieldname.' AS NUMERIC) AS INTEGER)'; // From char to integer}$results[] = $alterstmt;}// If the default has changed or we have performed one change in specsif ($defaultchanged || $specschanged) {$default_clause = $this->getDefaultClause($xmldb_field);if ($default_clause) {$sql = 'ALTER TABLE ' . $tablename . ' ALTER COLUMN ' . $fieldname . ' SET' . $default_clause; // Add default clause$results[] = $sql;} else {if (!$specschanged) { // Only drop default if we haven't performed one specs change$results[] = 'ALTER TABLE ' . $tablename . ' ALTER COLUMN ' . $fieldname . ' DROP DEFAULT'; // Drop default clause}}}// If the not null has changedif ($notnullchanged) {if ($xmldb_field->getNotnull()) {$results[] = 'ALTER TABLE ' . $tablename . ' ALTER COLUMN ' . $fieldname . ' SET NOT NULL';} else {$results[] = 'ALTER TABLE ' . $tablename . ' ALTER COLUMN ' . $fieldname . ' DROP NOT NULL';}}// Return the resultsreturn $results;}/*** Given one xmldb_table and one xmldb_field, return the SQL statements needed to add its default* (usually invoked from getModifyDefaultSQL()** @param xmldb_table $xmldb_table The xmldb_table object instance.* @param xmldb_field $xmldb_field The xmldb_field object instance.* @return array Array of SQL statements to create a field's default.*/public function getCreateDefaultSQL($xmldb_table, $xmldb_field) {// Just a wrapper over the getAlterFieldSQL() function for PostgreSQL that// is capable of handling defaultsreturn $this->getAlterFieldSQL($xmldb_table, $xmldb_field);}/*** Given one xmldb_table and one xmldb_field, return the SQL statements needed to drop its default* (usually invoked from getModifyDefaultSQL()** Note that this method may be dropped in future.** @param xmldb_table $xmldb_table The xmldb_table object instance.* @param xmldb_field $xmldb_field The xmldb_field object instance.* @return array Array of SQL statements to create a field's default.** @todo MDL-31147 Moodle 2.1 - Drop getDropDefaultSQL()*/public function getDropDefaultSQL($xmldb_table, $xmldb_field) {// Just a wrapper over the getAlterFieldSQL() function for PostgreSQL that// is capable of handling defaultsreturn $this->getAlterFieldSQL($xmldb_table, $xmldb_field);}/*** Adds slashes to string.* @param string $s* @return string The escaped string.*/public function addslashes($s) {// Postgres is gradually switching to ANSI quotes, we need to check what is expectedif (!isset($this->std_strings)) {$this->std_strings = ($this->mdb->get_field_sql("select setting from pg_settings where name = 'standard_conforming_strings'") === 'on');}if ($this->std_strings) {$s = str_replace("'", "''", $s);} else {// do not use php addslashes() because it depends on PHP quote settings!$s = str_replace('\\','\\\\',$s);$s = str_replace("\0","\\\0", $s);$s = str_replace("'", "\\'", $s);}return $s;}/*** Given one xmldb_table returns one string with the sequence of the table* in the table (fetched from DB)* The sequence name for Postgres has one standard name convention:* tablename_fieldname_seq* so we just calculate it and confirm it's present in pg_class** @param xmldb_table $xmldb_table The xmldb_table object instance.* @return string|bool If no sequence is found, returns false*/function getSequenceFromDB($xmldb_table) {$tablename = $this->getTableName($xmldb_table);$sequencename = $tablename . '_id_seq';if (!$this->mdb->get_record_sql("SELECT c.*FROM pg_catalog.pg_class cJOIN pg_catalog.pg_namespace as ns ON ns.oid = c.relnamespaceWHERE c.relname = ? AND c.relkind = 'S'AND (ns.nspname = current_schema() OR ns.oid = pg_my_temp_schema())",array($sequencename))) {$sequencename = false;}return $sequencename;}/*** Given one object name and it's type (pk, uk, fk, ck, ix, uix, seq, trg).** (MySQL requires the whole xmldb_table object to be specified, so we add it always)** This is invoked from getNameForObject().* Only some DB have this implemented.** @param string $object_name The object's name to check for.* @param string $type The object's type (pk, uk, fk, ck, ix, uix, seq, trg).* @param string $table_name The table's name to check in* @return bool If such name is currently in use (true) or no (false)*/public function isNameInUse($object_name, $type, $table_name) {switch($type) {case 'ix':case 'uix':case 'seq':if ($check = $this->mdb->get_records_sql("SELECT c.relnameFROM pg_class cJOIN pg_catalog.pg_namespace as ns ON ns.oid = c.relnamespaceWHERE lower(c.relname) = ?AND (ns.nspname = current_schema() OR ns.oid = pg_my_temp_schema())", array(strtolower($object_name)))) {return true;}break;case 'pk':case 'uk':case 'fk':case 'ck':if ($check = $this->mdb->get_records_sql("SELECT c.connameFROM pg_constraint cJOIN pg_catalog.pg_namespace as ns ON ns.oid = c.connamespaceWHERE lower(c.conname) = ?AND (ns.nspname = current_schema() OR ns.oid = pg_my_temp_schema())", array(strtolower($object_name)))) {return true;}break;case 'trg':if ($check = $this->mdb->get_records_sql("SELECT tgnameFROM pg_triggerWHERE lower(tgname) = ?", array(strtolower($object_name)))) {return true;}break;}return false; //No name in use found}/*** Returns an array of reserved words (lowercase) for this DB* @return array An array of database specific reserved words*/public static function getReservedWords() {// This file contains the reserved words for PostgreSQL databases// This file contains the reserved words for PostgreSQL databases// http://www.postgresql.org/docs/current/static/sql-keywords-appendix.html$reserved_words = array ('all', 'analyse', 'analyze', 'and', 'any', 'array', 'as', 'asc','asymmetric', 'authorization', 'between', 'binary', 'both', 'case','cast', 'check', 'collate', 'column', 'constraint', 'create', 'cross','current_date', 'current_role', 'current_time', 'current_timestamp','current_user', 'default', 'deferrable', 'desc', 'distinct', 'do','else', 'end', 'except', 'false', 'for', 'foreign', 'freeze', 'from','full', 'grant', 'group', 'having', 'ilike', 'in', 'initially', 'inner','intersect', 'into', 'is', 'isnull', 'join', 'leading', 'left', 'like','limit', 'localtime', 'localtimestamp', 'natural', 'new', 'not','notnull', 'null', 'off', 'offset', 'old', 'on', 'only', 'or', 'order','outer', 'overlaps', 'placing', 'primary', 'references', 'returning', 'right', 'select','session_user', 'similar', 'some', 'symmetric', 'table', 'then', 'to','trailing', 'true', 'union', 'unique', 'user', 'using', 'verbose','when', 'where', 'with');return $reserved_words;}}