silverstripe-framework/core/model/Database.php
Sam Minnee 9b1487c376 Dramatically improved performance of db/build
git-svn-id: svn://svn.silverstripe.com/silverstripe/open/modules/sapphire/trunk@40035 467b73ca-7a2a-4603-9d3b-597d59a354a9
2007-08-15 02:50:39 +00:00

525 lines
15 KiB
PHP
Executable File

<?php
/**
* @package sapphire
* @subpackage core
*/
/**
* Abstract database connectivity class.
* Sub-classes of this implement the actual database connection libraries
*/
abstract class Database extends Object {
/**
* Connection object to the database.
* @param resource
*/
static $globalConn;
/**
* If this is false, then information about database operations
* will be displayed, eg creation of tables.
* @param boolean
*/
public static $supressOutput = false;
/**
* Execute the given SQL query.
* This abstract function must be defined by subclasses as part of the actual implementation.
* It should return a subclass of Query as the result.
* @param string $sql The SQL query to execute
* @param int $errorLevel The level of error reporting to enable for the query
* @return Query
*/
abstract function query($sql, $errorLevel = E_USER_ERROR);
/**
* Get the autogenerated ID from the previous INSERT query.
* @return int
*/
abstract function getGeneratedID();
/**
* Check if the connection to the database is active.
* @return boolean
*/
abstract function isActive();
/**
* Create the database and connect to it. This can be called if the
* initial database connection is not successful because the database
* does not exist.
* @return boolean Returns true if successful
*/
abstract function createDatabase();
/**
* Create a new table.
* The table will have a single field - the integer key ID.
* @param string $table Name of table to create.
*/
abstract function createTable($table, $fields = null, $indexes = null);
/**
* Alter a table's schema.
*/
abstract function alterTable($table, $newFields, $newIndexes, $alteredFields, $alteredIndexes);
/**
* Rename a table.
* @param string $oldTableName The old table name.
* @param string $newTableName The new table name.
*/
abstract function renameTable($oldTableName, $newTableName);
/**
* Create a new field on a table.
* @param string $table Name of the table.
* @param string $field Name of the field to add.
* @param string $spec The field specification, eg 'INTEGER NOT NULL'
*/
abstract function createField($table, $field, $spec);
/**
* Get a list of all the fields for the given table.
* Returns a map of field name => field spec.
* @param string $table The table name.
* @return array
*/
protected abstract function fieldList($table);
/**
* Returns a list of all tables in the database.
* The table names will be in lower case.
* @return array
*/
protected abstract function tableList();
/**
* The table list, generated by the tableList() function.
* Used by the requireTable() function.
* @var array
*/
protected $tableList;
/**
* The field list, generated by the fieldList() function.
* An array of maps of field name => field spec, indexed
* by table name.
* @var array
*/
protected $fieldList;
/**
* The index list for each table, generated by the indexList() function.
* An map from table name to an array of index names.
* @var array
*/
protected $indexList;
/**
* Large array structure that represents a schema update transaction
*/
protected $schemaUpdateTransaction;
/**
* Start a schema-updating transaction.
* All calls to requireTable/Field/Index will keep track of the changes requested, but not actually do anything.
* Once
*/
function beginSchemaUpdate() {
$this->tableList = $this->tableList();
$this->indexList = null;
$this->fieldList = null;
$this->schemaUpdateTransaction = array();
}
function endSchemaUpdate() {
foreach($this->schemaUpdateTransaction as $tableName => $changes) {
switch($changes['command']) {
case 'create':
$this->createTable($tableName, $changes['newFields'], $changes['newIndexes']);
break;
case 'alter':
$this->alterTable($tableName, $changes['newFields'], $changes['newIndexes'],
$changes['alteredFields'], $changes['alteredIndexes']);
break;
}
}
$this->schemaUpdateTransaction = null;
}
// Transactional schema altering functions - they don't do anyhting except for update schemaUpdateTransaction
function transCreateTable($table) {
$this->schemaUpdateTransaction[$table] = array('command' => 'create');
}
function transCreateField($table, $field, $schema) {
$this->schemaUpdateTransaction[$table]['newFields'][$field] = $schema;
}
function transCreateIndex($table, $index, $schema) {
$this->schemaUpdateTransaction[$table]['newIndexes'][$index] = $schema;
}
function transAlterField($table, $field, $schema) {
$this->schemaUpdateTransaction[$table]['alteredFields'][$field] = $schema;
}
function transAlterIndex($table, $index, $schema) {
$this->schemaUpdateTransaction[$table]['alteredIndexes'][$index] = $schema;
}
/**
* Generate the following table in the database, modifying whatever already exists
* as necessary.
* @param string $table The name of the table
* @param string $fieldSchema A list of the fields to create, in the same form as DataObject::$db
* @param string $indexSchema A list of indexes to create. The keys of the array are the names of the index.
* The values of the array can be one of:
* - true: Create a single column index on the field named the same as the index.
* - array('fields' => array('A','B','C'), 'type' => 'index/unique/fulltext'): This gives you full
* control over the index.
*/
function requireTable($table, $fieldSchema = null, $indexSchema = null) {
if(!isset($this->tableList[strtolower($table)])) {
$this->transCreateTable($table);
if(!Database::$supressOutput) {
echo "<li style=\"color: orange\">Table $table: created</li>";
}
} else {
$this->checkAndRepairTable($table);
}
// Create custom fields
if($fieldSchema) {
foreach($fieldSchema as $fieldName => $fieldSpec) {
$fieldObj = eval(ViewableData::castingObjectCreator($fieldSpec));
$fieldObj->setTable($table);
$fieldObj->requireField();
}
}
// Create custom indexes
if($indexSchema) {
foreach($indexSchema as $indexName => $indexDetails) {
$this->requireIndex($table, $indexName, $indexDetails);
}
}
}
/**
* If the given table exists, move it out of the way by renaming it to _obsolete_(tablename).
* @param string $table The table name.
*/
function dontRequireTable($table) {
if(!isset($this->tableList)) $this->tableList = $this->tableList();
if(isset($this->tableList[strtolower($table)])) {
while($this->tableList[strtolower("_obsolete_{$table}$suffix")]) {
$suffix = $suffix ? ($suffix+1) : 2;
}
$this->renameTable($table, "_obsolete_{$table}$suffix");
if(!Database::$supressOutput) {
echo "<li style=\"color: orange\">Table $table: renamed to _obsolete_{$table}$suffix</li>";
}
}
}
/**
* Generate the given index in the database, modifying whatever already exists as necessary.
* @param string $table The table name.
* @param string $index The index name.
* @param string|boolean $spec The specification of the index. See requireTable() for more information.
*/
function requireIndex($table, $index, $spec) {
if($spec === true) {
$spec = "($index)";
}
$spec = ereg_replace(" *, *",",",$spec);
if(!isset($this->tableList[strtolower($table)])) $newTable = true;
if(!$newTable && !isset($this->indexList[$table])) {
$this->indexList[$table] = $this->indexList($table);
}
if($newTable || !isset($this->indexList[$table][$index])) {
$this->transCreateIndex($table, $index, $spec);
if(!Database::$supressOutput) {
echo "<li style=\"color: red\">Index $table.$index: created as $spec</li>";
}
} else if($this->indexList[$table][$index] != $spec) {
$this->transAlterIndex($table, $index, $spec);
if(!Database::$supressOutput) {
echo "<li style=\"color: orange\">Index $table.$index: changed to $spec <i style=\"color: #AAA\">(from {$this->indexList[$table][$index]})</i></li>";
}
}
}
/**
* Generate the given field on the table, modifying whatever already exists as necessary.
* @param string $table The table name.
* @param string $field The field name.
* @param string $spec The field specification.
*/
function requireField($table, $field, $spec) {
Profiler::mark('requireField');
// Collations didn't come in until MySQL 4.1. Anything earlier will throw a syntax error if you try and use
// collations.
if(!$this->supportsCollations()) {
$spec = eregi_replace(' *character set [^ ]+( collate [^ ]+)?( |$)','\\2',$spec);
}
if(!isset($this->tableList[strtolower($table)])) $newTable = true;
if(!$newTable && !isset($this->fieldList[$table])) {
$this->fieldList[$table] = $this->fieldList($table);
}
if($newTable || !isset($this->fieldList[$table][$field])) {
Profiler::mark('createField');
$this->transCreateField($table, $field, $spec);
Profiler::unmark('createField');
if(!Database::$supressOutput) {
echo "<li style=\"color: red\">Field $table.$field: created as $spec</li>";
}
} else if($this->fieldList[$table][$field] != $spec) {
Profiler::mark('alterField');
$this->transAlterField($table, $field, $spec);
Profiler::unmark('alterField');
if(!Database::$supressOutput) {
echo "<li style=\"color: orange\">Field $table.$field: changed to $spec <i style=\"color: #AAA\">(from {$this->fieldList[$table][$field]})</i></li>";
}
}
Profiler::unmark('requireField');
}
/**
* Execute a complex manipulation on the database.
* A manipulation is an array of insert / or update sequences. The keys of the array are table names,
* and the values are map containing 'command' and 'fields'. Command should be 'insert' or 'update',
* and fields should be a map of field names to field values, including quotes. The field value can
* also be a SQL function or similar.
* @param array $manipulation
*/
function manipulate($manipulation) {
foreach($manipulation as $table => $writeInfo) {
if(isset($writeInfo['fields']) && $writeInfo['fields']) {
$fieldList = array();
foreach($writeInfo['fields'] as $fieldName => $fieldVal) {
$fieldList[] = "`$fieldName` = $fieldVal";
}
$fieldList = implode(", ", $fieldList);
if(!isset($writeInfo['where']) && isset($writeInfo['id'])) {
$writeInfo['where'] = "ID = $writeInfo[id]";
}
switch($writeInfo['command']) {
case "update":
$sql = "update `$table` SET $fieldList where $writeInfo[where]";
$this->query($sql);
// If numAffectedRecord = 0, then we want to run instert instead
if(!$this->affectedRows()) {
if(!isset($writeInfo['fields']['ID']) && isset($writeInfo['id'])) {
$fieldList .= ", ID = $writeInfo[id]";
}
$sql = "insert into `$table` SET $fieldList";
$this->query($sql, null);
}
break;
case "insert":
if(!isset($writeInfo['fields']['ID']) && isset($writeInfo['id'])) {
$fieldList .= ", ID = $writeInfo[id]";
}
$sql = "insert into `$table` SET $fieldList";
$this->query($sql);
break;
default:
$sql = null;
user_error("Database::manipulate() Can't recognise command '$writeInfo[command]'", E_USER_ERROR);
}
}
}
}
/**
* Error handler for database errors.
* All database errors will call this function to report the error. It isn't a static function;
* it will be called on the object itself and as such can be overridden in a subclass.
* @todo hook this into a more well-structured error handling system.
* @param string $msg The error message.
* @param int $errorLevel The level of the error to throw.
*/
function databaseError($msg, $errorLevel = E_USER_ERROR) {
user_error("DATABASE ERROR: $msg", $errorLevel);
}
/**
* Enable supression of database messages.
*/
function quiet() {
Database::$supressOutput = true;
}
}
/**
* Abstract query-result class.
* Once again, this should be subclassed by an actual database implementation. It will only
* ever be constructed by a subclass of Database. The result of a database query - an iteratable object that's returned by DB::Query
*
* Primarily, the Query class takes care of the iterator plumbing, letting the subclasses focusing
* on providing the specific data-access methods that are required: {@link nextRecord()}, {@link numRecords()}
* and {@link seek()}
*/
abstract class Query extends Object implements Iterator {
/**
* The current record in the interator.
* @var array
*/
private $currentRecord = null;
/**
* The number of the current row in the interator.
* @var int
*/
private $rowNum = -1;
/**
* Return an array containing all values in the leftmost column.
* @return array
*/
public function column() {
foreach($this as $record) {
$column[] = reset($record);
}
return isset($column) ? $column : null;
}
/**
* Return an array containing all values in the leftmost column, where the keys are the
* same as the values.
* @return array
*/
public function keyedColumn() {
foreach($this as $record) {
$val = reset($record);
$column[$val] = $val;
}
return $column;
}
/**
* Return a map from the first column to the second column.
* @return array
*/
public function map() {
foreach($this as $record) {
$key = reset($record);
$val = next($record);
$column[$key] = $val;
}
return $column;
}
/**
* Returns the next record in the iterator.
* @return array
*/
public function record() {
return $this->next();
}
/**
* Returns the first column of the first record.
* @return string
*/
public function value() {
foreach($this as $record) {
return reset($record);
}
}
/**
* Iterator function implementation. Rewind the iterator to the first item and return it.
* Makes use of {@link seek()} and {@link numRecords()}, takes care of the plumbing.
* @return array
*/
public function rewind() {
if($this->numRecords() > 0) {
return $this->seek(0);
}
}
/**
* Iterator function implementation. Return the current item of the iterator.
* @return array
*/
public function current() {
if(!$this->currentRecord) {
return $this->next();
} else {
return $this->currentRecord;
}
}
/**
* Iterator function implementation. Return the first item of this iterator.
* @return array
*/
public function first() {
$this->rewind();
return $this->current();
}
/**
* Iterator function implementation. Return the row number of the current item.
* @return int
*/
public function key() {
return $this->rowNum;
}
/**
* Iterator function implementation. Return the next record in the iterator.
* Makes use of {@link nextRecord()}, takes care of the plumbing.
* @return array
*/
public function next() {
$this->currentRecord = $this->nextRecord();
$this->rowNum++;
return $this->currentRecord;
}
/**
* Iterator function implementation. Check if the iterator is pointing to a valid item.
* @return boolean
*/
public function valid() {
return $this->current() !== false;
}
/**
* Return the next record in the query result.
* @return array
*/
abstract function nextRecord();
/**
* Return the total number of items in the query result.
* @return int
*/
abstract function numRecords();
/**
* Go to a specific row number in the query result and return the record.
* @param int $rowNum Tow number to go to.
* @return array
*/
abstract function seek($rowNum);
}
?>