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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/>.
/**
* Oracle 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 Oracle
* 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 oracle_sql_generator extends sql_generator {
// Only set values that are different from the defaults present in XMLDBgenerator
/**
* @var string To be automatically added at the end of each statement.
* note: Using "/" because the standard ";" isn't good for stored procedures (triggers)
*/
public $statement_end = "\n/";
/** @var string Proper type for NUMBER(x) in this DB. */
public $number_type = 'NUMBER';
/**
* @var string To define the default to set for NOT NULLs CHARs without default (null=do nothing).
* note: Using this whitespace here because Oracle doesn't distinguish empty and null! :-(
*/
public $default_for_char = ' ';
/** @var bool To specify if the generator must use some DEFAULT clause to drop defaults.*/
public $drop_default_value_required = true;
/** @var string The DEFAULT clause required to drop defaults.*/
public $drop_default_value = null;
/** @var bool To decide if the default clause of each field must go after the null clause.*/
public $default_after_null = false;
/** @var bool True if the generator needs to add extra code to generate the sequence fields.*/
public $sequence_extra_code = true;
/** @var string The particular name for inline sequences in this generator.*/
public $sequence_name = '';
/** @var string The SQL template to alter columns where the 'TABLENAME' and 'COLUMNSPECS' keywords are dynamically replaced.*/
public $alter_column_sql = 'ALTER TABLE TABLENAME MODIFY (COLUMNSPECS)';
/** @var int var ugly Oracle hack - size of the sequences values cache (20 = Default)*/
public $sequence_cache_size = 20;
/**
* 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 (is_string($table)) {
$tablename = $table;
$xmldb_table = new xmldb_table($tablename);
} else {
$tablename = $table->getName();
$xmldb_table = $table;
}
// From http://www.acs.ilstu.edu/docs/oracle/server.101/b10759/statements_2011.htm
$value = (int)$this->mdb->get_field_sql('SELECT MAX(id) FROM {'.$tablename.'}');
$value++;
$seqname = $this->getSequenceFromDB($xmldb_table);
if (!$seqname) {
// Fallback, seqname not found, something is wrong. Inform and use the alternative getNameForObject() method
$seqname = $this->getNameForObject($table, 'id', 'seq');
}
return array ("DROP SEQUENCE $seqname",
"CREATE SEQUENCE $seqname START WITH $value INCREMENT BY 1 NOMAXVALUE CACHE $this->sequence_cache_size");
}
/**
* Given one xmldb_table, returns it's correct name, depending of all the parametrization
* Overridden to allow change of names in temp tables
*
* @param xmldb_table table whose name we want
* @param boolean to specify if the name must be quoted (if reserved word, only!)
* @return string the correct name of the table
*/
public function getTableName(xmldb_table $xmldb_table, $quoted=true) {
// Get the name, supporting special oci names for temp tables
if ($this->temptables->is_temptable($xmldb_table->getName())) {
$tablename = $this->temptables->get_correct_name($xmldb_table->getName());
} else {
$tablename = $this->prefix . $xmldb_table->getName();
}
// Apply quotes optionally
if ($quoted) {
$tablename = $this->getEncQuoted($tablename);
}
return $tablename;
}
public function getCreateIndexSQL($xmldb_table, $xmldb_index) {
if ($error = $xmldb_index->validateDefinition($xmldb_table)) {
throw new coding_exception($error);
}
$indexfields = $this->getEncQuoted($xmldb_index->getFields());
$unique = '';
$suffix = 'ix';
if ($xmldb_index->getUnique()) {
$unique = ' UNIQUE';
$suffix = 'uix';
$nullablefields = $this->get_nullable_fields_in_index($xmldb_table, $xmldb_index);
if ($nullablefields) {
// If this is a unique index with nullable fields, then we have to
// apply the work-around from https://community.oracle.com/message/9518046#9518046.
//
// For example if you have a unique index on the three columns
// (required, option1, option2) where the first one is non-null,
// and the others nullable, then the SQL will end up as
//
// CREATE UNIQUE INDEX index_name ON table_name (
// CASE WHEN option1 IS NOT NULL AND option2 IS NOT NULL THEN required ELSE NULL END,
// CASE WHEN option1 IS NOT NULL AND option2 IS NOT NULL THEN option1 ELSE NULL END,
// CASE WHEN option1 IS NOT NULL AND option2 IS NOT NULL THEN option2 ELSE NULL END)
//
// Basically Oracle behaves according to the standard if either
// none of the columns are NULL or all columns contain NULL. Therefore,
// if any column is NULL, we treat them all as NULL for the index.
$conditions = [];
foreach ($nullablefields as $fieldname) {
$conditions[] = $this->getEncQuoted($fieldname) .
' IS NOT NULL';
}
$condition = implode(' AND ', $conditions);
$updatedindexfields = [];
foreach ($indexfields as $fieldname) {
$updatedindexfields[] = 'CASE WHEN ' . $condition . ' THEN ' .
$fieldname . ' ELSE NULL END';
}
$indexfields = $updatedindexfields;
}
}
$index = 'CREATE' . $unique . ' INDEX ';
$index .= $this->getNameForObject($xmldb_table->getName(), implode(', ', $xmldb_index->getFields()), $suffix);
$index .= ' ON ' . $this->getTableName($xmldb_table);
$index .= ' (' . implode(', ', $indexfields) . ')';
return array($index);
}
/**
* 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 (.*)/s', 'CREATE GLOBAL TEMPORARY TABLE $1 ON COMMIT PRESERVE ROWS', $sqlarr);
return $sqlarr;
}
/**
* Given one correct xmldb_table, returns the SQL statements
* to drop it (inside one array).
*
* @param xmldb_table $xmldb_table The table to drop.
* @return array SQL statement(s) for dropping the specified table.
*/
public function getDropTableSQL($xmldb_table) {
$sqlarr = parent::getDropTableSQL($xmldb_table);
if ($this->temptables->is_temptable($xmldb_table->getName())) {
array_unshift($sqlarr, "TRUNCATE TABLE ". $this->getTableName($xmldb_table)); // oracle requires truncate before being able to drop a temp table
}
return $sqlarr;
}
/**
* 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: // See http://www.acs.ilstu.edu/docs/oracle/server.101/b10759/sql_elements001.htm#sthref86.
if (empty($xmldb_length)) {
$xmldb_length = 10;
}
$dbtype = 'NUMBER(' . $xmldb_length . ')';
break;
case XMLDB_TYPE_FLOAT:
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_CHAR:
// Do not use NVARCHAR2 here because it has hardcoded 1333 char limit,
// VARCHAR2 allows us to create larger fields that error out later during runtime
// only when too many non-ascii utf-8 chars present.
$dbtype = 'VARCHAR2';
if (empty($xmldb_length)) {
$xmldb_length='255';
}
$dbtype .= '(' . $xmldb_length . ' CHAR)'; // CHAR is required because BYTE is the default
break;
case XMLDB_TYPE_TEXT:
$dbtype = 'CLOB';
break;
case XMLDB_TYPE_BINARY:
$dbtype = 'BLOB';
break;
case XMLDB_TYPE_DATETIME:
$dbtype = 'DATE';
break;
}
return $dbtype;
}
/**
* Returns the code (array of statements) needed
* to create one sequence for the xmldb_table and xmldb_field passed in.
*
* @param xmldb_table $xmldb_table The xmldb_table object instance.
* @param xmldb_field $xmldb_field The xmldb_field object instance.
* @return array Array of SQL statements to create the sequence.
*/
public function getCreateSequenceSQL($xmldb_table, $xmldb_field) {
$results = array();
$sequence_name = $this->getNameForObject($xmldb_table->getName(), $xmldb_field->getName(), 'seq');
$sequence = "CREATE SEQUENCE $sequence_name START WITH 1 INCREMENT BY 1 NOMAXVALUE CACHE $this->sequence_cache_size";
$results[] = $sequence;
$results = array_merge($results, $this->getCreateTriggerSQL ($xmldb_table, $xmldb_field, $sequence_name));
return $results;
}
/**
* Returns the code needed to create one trigger for the xmldb_table and xmldb_field passed
*
* @param xmldb_table $xmldb_table The xmldb_table object instance.
* @param xmldb_field $xmldb_field The xmldb_field object instance.
* @param string $sequence_name
* @return array Array of SQL statements to create the sequence.
*/
public function getCreateTriggerSQL($xmldb_table, $xmldb_field, $sequence_name) {
$trigger_name = $this->getNameForObject($xmldb_table->getName(), $xmldb_field->getName(), 'trg');
$trigger = "CREATE TRIGGER " . $trigger_name;
$trigger.= "\n BEFORE INSERT";
$trigger.= "\nON " . $this->getTableName($xmldb_table);
$trigger.= "\n FOR EACH ROW";
$trigger.= "\nBEGIN";
$trigger.= "\n IF :new." . $this->getEncQuoted($xmldb_field->getName()) . ' IS NULL THEN';
$trigger.= "\n SELECT " . $sequence_name . '.nextval INTO :new.' . $this->getEncQuoted($xmldb_field->getName()) . " FROM dual;";
$trigger.= "\n END IF;";
$trigger.= "\nEND;";
return array($trigger);
}
/**
* Returns the code needed to drop one sequence for the xmldb_table and xmldb_field passed
* Can, optionally, specify if the underlying trigger will be also dropped
*
* @param xmldb_table $xmldb_table The xmldb_table object instance.
* @param xmldb_field $xmldb_field The xmldb_field object instance.
* @param bool $include_trigger
* @return array Array of SQL statements to create the sequence.
*/
public function getDropSequenceSQL($xmldb_table, $xmldb_field, $include_trigger=false) {
$result = array();
if ($sequence_name = $this->getSequenceFromDB($xmldb_table)) {
$result[] = "DROP SEQUENCE " . $sequence_name;
}
if ($trigger_name = $this->getTriggerFromDB($xmldb_table) && $include_trigger) {
$result[] = "DROP TRIGGER " . $trigger_name;
}
return $result;
}
/**
* 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 drop
*
* @param xmldb_table $xmldb_table The xmldb_table object instance.
* @return array Array of extra SQL statements to drop a table.
*/
public function getDropTableExtraSQL($xmldb_table) {
$xmldb_field = new xmldb_field('id'); // Fields having sequences should be exclusively, id.
return $this->getDropSequenceSQL($xmldb_table, $xmldb_field, false);
}
/**
* 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();
$xmldb_field = new xmldb_field('id'); // Fields having sequences should be exclusively, id.
$oldseqname = $this->getSequenceFromDB($xmldb_table);
$newseqname = $this->getNameForObject($newname, $xmldb_field->getName(), 'seq');
$oldtriggername = $this->getTriggerFromDB($xmldb_table);
$newtriggername = $this->getNameForObject($newname, $xmldb_field->getName(), 'trg');
// Drop old trigger (first of all)
$results[] = "DROP TRIGGER " . $oldtriggername;
// Rename the sequence, disablig CACHE before and enablig it later
// to avoid consuming of values on rename
$results[] = 'ALTER SEQUENCE ' . $oldseqname . ' NOCACHE';
$results[] = 'RENAME ' . $oldseqname . ' TO ' . $newseqname;
$results[] = 'ALTER SEQUENCE ' . $newseqname . ' CACHE ' . $this->sequence_cache_size;
// Create new trigger
$newt = new xmldb_table($newname); // Temp table for trigger code generation
$results = array_merge($results, $this->getCreateTriggerSQL($newt, $xmldb_field, $newseqname));
return $results;
}
/**
* Given one xmldb_table and one xmldb_field, return the SQL statements needed to alter the field in the table.
*
* Oracle has some severe limits:
* - clob and blob fields doesn't allow type to be specified
* - error is dropped if the null/not null clause is specified and hasn't changed
* - changes in precision/decimals of numeric fields drop an ORA-1440 error
*
* @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) {
$skip_type_clause = is_null($skip_type_clause) ? $this->alter_column_skip_type : $skip_type_clause;
$skip_default_clause = is_null($skip_default_clause) ? $this->alter_column_skip_default : $skip_default_clause;
$skip_notnull_clause = is_null($skip_notnull_clause) ? $this->alter_column_skip_notnull : $skip_notnull_clause;
$results = array(); // To store all the needed SQL commands
// Get the quoted name of the table and field
$tablename = $this->getTableName($xmldb_table);
$fieldname = $xmldb_field->getName();
// Take a look to field metadata
$meta = $this->mdb->get_columns($xmldb_table->getName());
$metac = $meta[$fieldname];
$oldmetatype = $metac->meta_type;
$oldlength = $metac->max_length;
// To calculate the oldlength if the field is numeric, we need to perform one extra query
// because ADOdb has one bug here. http://phplens.com/lens/lensforum/msgs.php?id=15883
if ($oldmetatype == 'N') {
$uppertablename = strtoupper($tablename);
$upperfieldname = strtoupper($fieldname);
if ($col = $this->mdb->get_record_sql("SELECT cname, precision
FROM col
WHERE tname = ? AND cname = ?",
array($uppertablename, $upperfieldname))) {
$oldlength = $col->precision;
}
}
$olddecimals = empty($metac->scale) ? null : $metac->scale;
$oldnotnull = empty($metac->not_null) ? false : $metac->not_null;
$olddefault = empty($metac->default_value) || strtoupper($metac->default_value) == 'NULL' ? 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
$from_temp_fields = false; //By default don't assume we are going to use temporal fields
// Detect if we are changing the type of the column
if (($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')) {
$typechanged = false;
}
// Detect if precision has changed
if (($xmldb_field->getType() == XMLDB_TYPE_TEXT) ||
($xmldb_field->getType() == XMLDB_TYPE_BINARY) ||
($oldlength == -1) ||
($xmldb_field->getLength() == $oldlength)) {
$precisionchanged = false;
}
// Detect if decimal has changed
if (($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)) {
$decimalchanged = false;
}
// Detect if we are changing the default
if (($xmldb_field->getDefault() === null && $olddefault === null) ||
($xmldb_field->getDefault() === $olddefault) || //Check both equality and
("'" . $xmldb_field->getDefault() . "'" === $olddefault)) { //Equality with quotes because ADOdb returns the default with quotes
$defaultchanged = false;
}
// Detect if we are changing the nullability
if (($xmldb_field->getNotnull() === $oldnotnull)) {
$notnullchanged = false;
}
// If type has changed or precision or decimal has changed and we are in one numeric field
// - create one temp column with the new specs
// - fill the new column with the values from the old one
// - drop the old column
// - rename the temp column to the original name
if (($typechanged) || (($oldmetatype == 'N' || $oldmetatype == 'I') && ($precisionchanged || $decimalchanged))) {
$tempcolname = $xmldb_field->getName() . '___tmp'; // Short tmp name, surely not conflicting ever
if (strlen($tempcolname) > 30) { // Safeguard we don't excess the 30cc limit
$tempcolname = 'ongoing_alter_column_tmp';
}
// Prevent temp field to have both NULL/NOT NULL and DEFAULT constraints
$skip_notnull_clause = true;
$skip_default_clause = true;
$xmldb_field->setName($tempcolname);
// Drop the temp column, in case it exists (due to one previous failure in conversion)
// really ugly but we cannot enclose DDL into transaction :-(
if (isset($meta[$tempcolname])) {
$results = array_merge($results, $this->getDropFieldSQL($xmldb_table, $xmldb_field));
}
// Create the temporal column
$results = array_merge($results, $this->getAddFieldSQL($xmldb_table, $xmldb_field, $skip_type_clause, $skip_type_clause, $skip_notnull_clause));
// Copy contents from original col to the temporal one
// From TEXT to integer/number we need explicit conversion
if ($oldmetatype == 'X' && $xmldb_field->GetType() == XMLDB_TYPE_INTEGER) {
$results[] = 'UPDATE ' . $tablename . ' SET ' . $tempcolname . ' = CAST(' . $this->mdb->sql_compare_text($fieldname) . ' AS INT)';
} else if ($oldmetatype == 'X' && $xmldb_field->GetType() == XMLDB_TYPE_NUMBER) {
$results[] = 'UPDATE ' . $tablename . ' SET ' . $tempcolname . ' = CAST(' . $this->mdb->sql_compare_text($fieldname) . ' AS NUMBER)';
// Normal cases, implicit conversion
} else {
$results[] = 'UPDATE ' . $tablename . ' SET ' . $tempcolname . ' = ' . $fieldname;
}
// Drop the old column
$xmldb_field->setName($fieldname); //Set back the original field name
$results = array_merge($results, $this->getDropFieldSQL($xmldb_table, $xmldb_field));
// Rename the temp column to the original one
$results[] = 'ALTER TABLE ' . $tablename . ' RENAME COLUMN ' . $tempcolname . ' TO ' . $fieldname;
// Mark we have performed one change based in temp fields
$from_temp_fields = true;
// Re-enable the notnull and default sections so the general AlterFieldSQL can use it
$skip_notnull_clause = false;
$skip_default_clause = false;
// Disable the type section because we have done it with the temp field
$skip_type_clause = true;
// If new field is nullable, nullability hasn't changed
if (!$xmldb_field->getNotnull()) {
$notnullchanged = false;
}
// If new field hasn't default, default hasn't changed
if ($xmldb_field->getDefault() === null) {
$defaultchanged = false;
}
}
// If type and precision and decimals hasn't changed, prevent the type clause
if (!$typechanged && !$precisionchanged && !$decimalchanged) {
$skip_type_clause = true;
}
// If NULL/NOT NULL hasn't changed
// prevent null clause to be specified
if (!$notnullchanged) {
$skip_notnull_clause = true; // Initially, prevent the notnull clause
// But, if we have used the temp field and the new field is not null, then enforce the not null clause
if ($from_temp_fields && $xmldb_field->getNotnull()) {
$skip_notnull_clause = false;
}
}
// If default hasn't changed
// prevent default clause to be specified
if (!$defaultchanged) {
$skip_default_clause = true; // Initially, prevent the default clause
// But, if we have used the temp field and the new field has default clause, then enforce the default clause
if ($from_temp_fields) {
$default_clause = $this->getDefaultClause($xmldb_field);
if ($default_clause) {
$skip_notnull_clause = false;
}
}
}
// If arriving here, something is not being skipped (type, notnull, default), calculate the standard AlterFieldSQL
if (!$skip_type_clause || !$skip_notnull_clause || !$skip_default_clause) {
$results = array_merge($results, parent::getAlterFieldSQL($xmldb_table, $xmldb_field, $skip_type_clause, $skip_default_clause, $skip_notnull_clause));
return $results;
}
// Finally return results
return $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 Oracle that
// is capable of handling defaults
return $this->getAlterFieldSQL($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 Oracle that
// is capable of handling defaults
return $this->getAlterFieldSQL($xmldb_table, $xmldb_field);
}
/**
* Given one xmldb_table returns one string with the sequence of the table
* in the table (fetched from DB)
* The sequence name for oracle is calculated by looking the corresponding
* trigger and retrieving the sequence name from it (because sequences are
* independent elements)
* @param xmldb_table $xmldb_table The xmldb_table object instance.
* @return string|bool If no sequence is found, returns false
*/
public function getSequenceFromDB($xmldb_table) {
$tablename = strtoupper($this->getTableName($xmldb_table));
$prefixupper = strtoupper($this->prefix);
$sequencename = false;
if ($trigger = $this->mdb->get_record_sql("SELECT trigger_name, trigger_body
FROM user_triggers
WHERE table_name = ? AND trigger_name LIKE ?",
array($tablename, "{$prefixupper}%_ID%_TRG"))) {
// If trigger found, regexp it looking for the sequence name
preg_match('/.*SELECT (.*)\.nextval/i', $trigger->trigger_body, $matches);
if (isset($matches[1])) {
$sequencename = $matches[1];
}
}
return $sequencename;
}
/**
* Given one xmldb_table returns one string with the trigger
* in the table (fetched from DB)
*
* @param xmldb_table $xmldb_table The xmldb_table object instance.
* @return string|bool If no trigger is found, returns false
*/
public function getTriggerFromDB($xmldb_table) {
$tablename = strtoupper($this->getTableName($xmldb_table));
$prefixupper = strtoupper($this->prefix);
$triggername = false;
if ($trigger = $this->mdb->get_record_sql("SELECT trigger_name, trigger_body
FROM user_triggers
WHERE table_name = ? AND trigger_name LIKE ?",
array($tablename, "{$prefixupper}%_ID%_TRG"))) {
$triggername = $trigger->trigger_name;
}
return $triggername;
}
/**
* 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':
case 'trg':
if ($check = $this->mdb->get_records_sql("SELECT object_name
FROM user_objects
WHERE lower(object_name) = ?", array(strtolower($object_name)))) {
return true;
}
break;
case 'pk':
case 'uk':
case 'fk':
case 'ck':
if ($check = $this->mdb->get_records_sql("SELECT constraint_name
FROM user_constraints
WHERE lower(constraint_name) = ?", array(strtolower($object_name)))) {
return true;
}
break;
}
return false; //No name in use found
}
/**
* Adds slashes to string.
* @param string $s
* @return string The escaped string.
*/
public function addslashes($s) {
// do not use php addslashes() because it depends on PHP quote settings!
$s = str_replace("'", "''", $s);
return $s;
}
/**
* 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 Oracle databases
// from http://download-uk.oracle.com/docs/cd/B10501_01/server.920/a96540/ap_keywd.htm
$reserved_words = array (
'access', 'add', 'all', 'alter', 'and', 'any',
'as', 'asc', 'audit', 'between', 'by', 'char',
'check', 'cluster', 'column', 'comment',
'compress', 'connect', 'create', 'current',
'date', 'decimal', 'default', 'delete', 'desc',
'distinct', 'drop', 'else', 'exclusive', 'exists',
'file', 'float', 'for', 'from', 'grant', 'group',
'having', 'identified', 'immediate', 'in',
'increment', 'index', 'initial', 'insert',
'integer', 'intersect', 'into', 'is', 'level',
'like', 'lock', 'long', 'maxextents', 'minus',
'mlslabel', 'mode', 'modify', 'nchar', 'nclob', 'noaudit',
'nocompress', 'not', 'nowait', 'null', 'number', 'nvarchar2',
'of', 'offline', 'on', 'online', 'option', 'or',
'order', 'pctfree', 'prior', 'privileges',
'public', 'raw', 'rename', 'resource', 'revoke',
'row', 'rowid', 'rownum', 'rows', 'select',
'session', 'set', 'share', 'size', 'smallint',
'start', 'successful', 'synonym', 'sysdate',
'table', 'then', 'to', 'trigger', 'uid', 'union',
'unique', 'update', 'user', 'validate', 'values',
'varchar', 'varchar2', 'view', 'whenever',
'where', 'with'
);
return $reserved_words;
}
}