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doctrine2/lib/Doctrine/DatabasePlatform.php
2008-08-16 19:40:59 +00:00

976 lines
27 KiB
PHP

<?php
/*
* $Id$
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* This software consists of voluntary contributions made by many individuals
* and is licensed under the LGPL. For more information, see
* <http://www.phpdoctrine.org>.
*/
#namespace Doctrine::DBAL::Platforms;
/**
* Base class for all DatabasePlatforms. The DatabasePlatforms are the central
* point of abstraction of platform-specific behaviors, features and SQL dialects.
* They are a passive source of information.
*
* @since 2.0
* @author Roman Borschel <roman@code-factory.org>
* @author Lukas Smith <smith@pooteeweet.org> (PEAR MDB2 library)
*/
abstract class Doctrine_DatabasePlatform
{
/**
* Constructor.
*/
public function __construct() {}
/**
* Gets the character used for identifier quoting.
*
* @return string
*/
public function getIdentifierQuoteCharacter()
{
return '"';
}
/**
* Gets the string portion that starts an SQL comment.
*
* @return string
*/
public function getSqlCommentStartString()
{
return "--";
}
/**
* Gets the string portion that starts an SQL comment.
*
* @return string
*/
public function getSqlCommentEndString()
{
return "\n";
}
/**
* Gets the maximum length of a varchar field.
*
* @return integer
*/
public function getVarcharMaxLength()
{
return 255;
}
/**
* Gets all SQL wildcard characters of the platform.
*
* @return array
*/
public function getWildcards()
{
return array('%', '_');
}
/**
* Returns the regular expression operator.
*
* @return string
*/
public function getRegexpExpression()
{
throw new Doctrine_Expression_Exception('Regular expression operator is not supported by this database driver.');
}
/**
* Returns the average value of a column
*
* @param string $column the column to use
* @return string generated sql including an AVG aggregate function
*/
public function getAvgExpression($column)
{
$column = $this->getIdentifier($column);
return 'AVG(' . $column . ')';
}
/**
* Returns the number of rows (without a NULL value) of a column
*
* If a '*' is used instead of a column the number of selected rows
* is returned.
*
* @param string|integer $column the column to use
* @return string generated sql including a COUNT aggregate function
*/
public function getCountExpression($column)
{
$column = $this->getIdentifier($column);
return 'COUNT(' . $column . ')';
}
/**
* Returns the highest value of a column
*
* @param string $column the column to use
* @return string generated sql including a MAX aggregate function
*/
public function getMaxExpression($column)
{
$column = $this->getIdentifier($column);
return 'MAX(' . $column . ')';
}
/**
* Returns the lowest value of a column
*
* @param string $column the column to use
* @return string
*/
public function getMinExpression($column)
{
$column = $this->getIdentifier($column);
return 'MIN(' . $column . ')';
}
/**
* Returns the total sum of a column
*
* @param string $column the column to use
* @return string
*/
public function getSumExpression($column)
{
$column = $this->getIdentifier($column);
return 'SUM(' . $column . ')';
}
// scalar functions
/**
* Returns the md5 sum of a field.
*
* Note: Not SQL92, but common functionality
*
* @return string
*/
public function getMd5Expression($column)
{
$column = $this->getIdentifier($column);
return 'MD5(' . $column . ')';
}
/**
* Returns the length of a text field.
*
* @param string $expression1
* @param string $expression2
* @return string
*/
public function getLengthExpression($column)
{
$column = $this->getIdentifier($column);
return 'LENGTH(' . $column . ')';
}
/**
* Rounds a numeric field to the number of decimals specified.
*
* @param string $expression1
* @param string $expression2
* @return string
*/
public function getRoundExpression($column, $decimals = 0)
{
$column = $this->getIdentifier($column);
return 'ROUND(' . $column . ', ' . $decimals . ')';
}
/**
* Returns the remainder of the division operation
* $expression1 / $expression2.
*
* @param string $expression1
* @param string $expression2
* @return string
*/
public function getModExpression($expression1, $expression2)
{
$expression1 = $this->getIdentifier($expression1);
$expression2 = $this->getIdentifier($expression2);
return 'MOD(' . $expression1 . ', ' . $expression2 . ')';
}
/**
* trim
* returns the string $str with leading and proceeding space characters removed
*
* @param string $str literal string or column name
* @return string
*/
public function getTrimExpression($str)
{
return 'TRIM(' . $str . ')';
}
/**
* rtrim
* returns the string $str with proceeding space characters removed
*
* @param string $str literal string or column name
* @return string
*/
public function getRtrimExpression($str)
{
return 'RTRIM(' . $str . ')';
}
/**
* ltrim
* returns the string $str with leading space characters removed
*
* @param string $str literal string or column name
* @return string
*/
public function getLtrimExpression($str)
{
return 'LTRIM(' . $str . ')';
}
/**
* upper
* Returns the string $str with all characters changed to
* uppercase according to the current character set mapping.
*
* @param string $str literal string or column name
* @return string
*/
public function getUpperExpression($str)
{
return 'UPPER(' . $str . ')';
}
/**
* lower
* Returns the string $str with all characters changed to
* lowercase according to the current character set mapping.
*
* @param string $str literal string or column name
* @return string
*/
public function getLowerExpression($str)
{
return 'LOWER(' . $str . ')';
}
/**
* locate
* returns the position of the first occurrence of substring $substr in string $str
*
* @param string $substr literal string to find
* @param string $str literal string
* @return integer
*/
public function getLocateExpression($str, $substr)
{
return 'LOCATE(' . $str . ', ' . $substr . ')';
}
/**
* Returns the current system date.
*
* @return string
*/
public function getNowExpression()
{
return 'NOW()';
}
/**
* soundex
* Returns a string to call a function to compute the
* soundex encoding of a string
*
* The string "?000" is returned if the argument is NULL.
*
* @param string $value
* @return string SQL soundex function with given parameter
*/
public function getSoundexExpression($value)
{
throw new Doctrine_Expression_Exception('SQL soundex function not supported by this driver.');
}
/**
* return string to call a function to get a substring inside an SQL statement
*
* Note: Not SQL92, but common functionality.
*
* SQLite only supports the 2 parameter variant of this function
*
* @param string $value an sql string literal or column name/alias
* @param integer $position where to start the substring portion
* @param integer $length the substring portion length
* @return string SQL substring function with given parameters
*/
public function getSubstringExpression($value, $from, $len = null)
{
$value = $this->getIdentifier($value);
if ($len === null)
return 'SUBSTRING(' . $value . ' FROM ' . $from . ')';
else {
$len = $this->getIdentifier($len);
return 'SUBSTRING(' . $value . ' FROM ' . $from . ' FOR ' . $len . ')';
}
}
/**
* Returns a series of strings concatinated
*
* concat() accepts an arbitrary number of parameters. Each parameter
* must contain an expression
*
* @param string $arg1, $arg2 ... $argN strings that will be concatinated.
* @return string
*/
public function getConcatExpression()
{
$args = func_get_args();
return join(' || ' , $args);
}
/**
* Returns the SQL for a logical not.
*
* Example:
* <code>
* $q = new Doctrine_Query();
* $e = $q->expr;
* $q->select('*')->from('table')
* ->where($e->eq('id', $e->not('null'));
* </code>
*
* @return string a logical expression
*/
public function getNotExpression($expression)
{
$expression = $this->getIdentifier($expression);
return 'NOT(' . $expression . ')';
}
/**
* Returns the SQL to perform the same mathematical operation over an array
* of values or expressions.
*
* basicMath() accepts an arbitrary number of parameters. Each parameter
* must contain a value or an expression or an array with values or
* expressions.
*
* @param string $type the type of operation, can be '+', '-', '*' or '/'.
* @param string|array(string)
* @return string an expression
*/
private function getBasicMathExpression($type, array $args)
{
$elements = $this->getIdentifiers($args);
if (count($elements) < 1) {
return '';
}
if (count($elements) == 1) {
return $elements[0];
} else {
return '(' . implode(' ' . $type . ' ', $elements) . ')';
}
}
/**
* Returns the SQL to add values or expressions together.
*
* add() accepts an arbitrary number of parameters. Each parameter
* must contain a value or an expression or an array with values or
* expressions.
*
* Example:
* <code>
* $q = new Doctrine_Query();
* $e = $q->expr;
*
* $q->select('u.*')
* ->from('User u')
* ->where($e->eq($e->add('id', 2), 12));
* </code>
*
* @param string|array(string)
* @return string an expression
*/
public function getAddExpression(array $args)
{
return $this->basicMath('+', $args);
}
/**
* Returns the SQL to subtract values or expressions from eachother.
*
* subtract() accepts an arbitrary number of parameters. Each parameter
* must contain a value or an expression or an array with values or
* expressions.
*
* Example:
* <code>
* $q = new Doctrine_Query();
* $e = $q->expr;
*
* $q->select('u.*')
* ->from('User u')
* ->where($e->eq($e->sub('id', 2), 12));
* </code>
*
* @param string|array(string)
* @return string an expression
*/
public function getSubExpression(array $args)
{
return $this->basicMath('-', $args );
}
/**
* Returns the SQL to multiply values or expressions by eachother.
*
* multiply() accepts an arbitrary number of parameters. Each parameter
* must contain a value or an expression or an array with values or
* expressions.
*
* Example:
* <code>
* $q = new Doctrine_Query();
* $e = $q->expr;
*
* $q->select('u.*')
* ->from('User u')
* ->where($e->eq($e->mul('id', 2), 12));
* </code>
*
* @param string|array(string)
* @return string an expression
*/
public function getMulExpression(array $args)
{
return $this->basicMath('*', $args);
}
/**
* Returns the SQL to divide values or expressions by eachother.
*
* divide() accepts an arbitrary number of parameters. Each parameter
* must contain a value or an expression or an array with values or
* expressions.
*
* Example:
* <code>
* $q = new Doctrine_Query();
* $e = $q->expr;
*
* $q->select('u.*')
* ->from('User u')
* ->where($e->eq($e->div('id', 2), 12));
* </code>
*
* @param string|array(string)
* @return string an expression
*/
public function getDivExpression(array $args)
{
return $this->basicMath('/', $args);
}
/**
* Returns the SQL to check if two values are equal.
*
* Example:
* <code>
* $q = new Doctrine_Query();
* $q->select('u.*')
* ->from('User u')
* ->where($q->expr->eq('id', 1));
* </code>
*
* @param string $value1 logical expression to compare
* @param string $value2 logical expression to compare with
* @return string logical expression
*/
public function getEqExpression($value1, $value2)
{
$value1 = $this->getIdentifier($value1);
$value2 = $this->getIdentifier($value2);
return $value1 . ' = ' . $value2;
}
/**
* Returns the SQL to check if two values are unequal.
*
* Example:
* <code>
* $q = new Doctrine_Query();
* $q->select('u.*')
* ->from('User u')
* ->where($q->expr->neq('id', 1));
* </code>
*
* @param string $value1 logical expression to compare
* @param string $value2 logical expression to compare with
* @return string logical expression
*/
public function getNeqExpression($value1, $value2)
{
$value1 = $this->getIdentifier($value1);
$value2 = $this->getIdentifier($value2);
return $value1 . ' <> ' . $value2;
}
/**
* Returns the SQL to check if one value is greater than another value.
*
* Example:
* <code>
* $q = new Doctrine_Query();
* $q->select('u.*')
* ->from('User u')
* ->where($q->expr->gt('id', 1));
* </code>
*
* @param string $value1 logical expression to compare
* @param string $value2 logical expression to compare with
* @return string logical expression
*/
public function getGtExpression($value1, $value2)
{
$value1 = $this->getIdentifier($value1);
$value2 = $this->getIdentifier($value2);
return $value1 . ' > ' . $value2;
}
/**
* Returns the SQL to check if one value is greater than or equal to
* another value.
*
* Example:
* <code>
* $q = new Doctrine_Query();
* $q->select('u.*')
* ->from('User u')
* ->where($q->expr->gte('id', 1));
* </code>
*
* @param string $value1 logical expression to compare
* @param string $value2 logical expression to compare with
* @return string logical expression
*/
public function getGteExpression($value1, $value2)
{
$value1 = $this->getIdentifier($value1);
$value2 = $this->getIdentifier($value2);
return $value1 . ' >= ' . $value2;
}
/**
* Returns the SQL to check if one value is less than another value.
*
* Example:
* <code>
* $q = new Doctrine_Query();
* $q->select('u.*')
* ->from('User u')
* ->where($q->expr->lt('id', 1));
* </code>
*
* @param string $value1 logical expression to compare
* @param string $value2 logical expression to compare with
* @return string logical expression
*/
public function getLtExpression($value1, $value2)
{
$value1 = $this->getIdentifier($value1);
$value2 = $this->getIdentifier($value2);
return $value1 . ' < ' . $value2;
}
/**
* Returns the SQL to check if one value is less than or equal to
* another value.
*
* Example:
* <code>
* $q = new Doctrine_Query();
* $q->select('u.*')
* ->from('User u')
* ->where($q->expr->lte('id', 1));
* </code>
*
* @param string $value1 logical expression to compare
* @param string $value2 logical expression to compare with
* @return string logical expression
*/
public function getLteExpression($value1, $value2)
{
$value1 = $this->getIdentifier($value1);
$value2 = $this->getIdentifier($value2);
return $value1 . ' <= ' . $value2;
}
/**
* Returns the SQL to check if a value is one in a set of
* given values..
*
* in() accepts an arbitrary number of parameters. The first parameter
* must always specify the value that should be matched against. Successive
* must contain a logical expression or an array with logical expressions.
* These expressions will be matched against the first parameter.
*
* Example:
* <code>
* $q = new Doctrine_Query();
* $q->select('u.*')
* ->from('User u')
* ->where($q->expr->in( 'id', array(1,2,3)));
* </code>
*
* @param string $column the value that should be matched against
* @param string|array(string) values that will be matched against $column
* @return string logical expression
*/
public function getInExpression($column, $values)
{
if ( ! is_array($values)) {
$values = array($values);
}
$values = $this->getIdentifiers($values);
$column = $this->getIdentifier($column);
if (count($values) == 0) {
throw new Doctrine_Expression_Exception('Values array for IN operator should not be empty.');
}
return $column . ' IN (' . implode(', ', $values) . ')';
}
/**
* Returns SQL that checks if a expression is null.
*
* Example:
* <code>
* $q = new Doctrine_Query();
* $q->select('u.*')
* ->from('User u')
* ->where($q->expr->isNull('id'));
* </code>
*
* @param string $expression the expression that should be compared to null
* @return string logical expression
*/
public function getIsNullExpression($expression)
{
$expression = $this->getIdentifier($expression);
return $expression . ' IS NULL';
}
/**
* Returns SQL that checks if a expression is not null.
*
* Example:
* <code>
* $q = new Doctrine_Query();
* $q->select('u.*')
* ->from('User u')
* ->where($q->expr->isNotNull('id'));
* </code>
*
* @param string $expression the expression that should be compared to null
* @return string logical expression
*/
public function getIsNotNullExpression($expression)
{
$expression = $this->getIdentifier($expression);
return $expression . ' IS NOT NULL';
}
/**
* Returns SQL that checks if an expression evaluates to a value between
* two values.
*
* The parameter $expression is checked if it is between $value1 and $value2.
*
* Note: There is a slight difference in the way BETWEEN works on some databases.
* http://www.w3schools.com/sql/sql_between.asp. If you want complete database
* independence you should avoid using between().
*
* Example:
* <code>
* $q = new Doctrine_Query();
* $q->select('u.*')
* ->from('User u')
* ->where($q->expr->between('id', 1, 5));
* </code>
*
* @param string $expression the value to compare to
* @param string $value1 the lower value to compare with
* @param string $value2 the higher value to compare with
* @return string logical expression
*/
public function getBetweenExpression($expression, $value1, $value2)
{
$expression = $this->getIdentifier($expression);
$value1 = $this->getIdentifier($value1);
$value2 = $this->getIdentifier($value2);
return $expression . ' BETWEEN ' .$value1 . ' AND ' . $value2;
}
/**
* Returns global unique identifier
*
* @return string to get global unique identifier
*/
public function getGuidExpression()
{
throw new Doctrine_Expression_Exception('method not implemented');
}
/**
* returns arcus cosine SQL string
*
* @return string
*/
public function getAcosExpression($value)
{
return 'ACOS(' . $value . ')';
}
/**
* sin
*
* @param string $value
* @return void
*/
public function getSinExpression($value)
{
return 'SIN(' . $value . ')';
}
/**
* pi
*
* @return void
*/
public function getPiExpression()
{
return 'PI()';
}
/**
* cos
*
* @param string $value
* @return void
* @author Jonathan H. Wage
*/
public function getCosExpression($value)
{
return 'COS(' . $value . ')';
}
/**
* build a pattern matching string
*
* EXPERIMENTAL
*
* WARNING: this function is experimental and may change signature at
* any time until labelled as non-experimental
*
* @access public
*
* @param array $pattern even keys are strings, odd are patterns (% and _)
* @param string $operator optional pattern operator (LIKE, ILIKE and maybe others in the future)
* @param string $field optional field name that is being matched against
* (might be required when emulating ILIKE)
*
* @return string SQL pattern
*/
public function getMatchPatternExpression($pattern, $operator = null, $field = null)
{
throw new Doctrine_Expression_Exception("Method not implemented.");
}
/**
* Obtain DBMS specific SQL code portion needed to declare an text type
* field to be used in statements like CREATE TABLE.
*
* @param array $field associative array with the name of the properties
* of the field being declared as array indexes. Currently, the types
* of supported field properties are as follows:
*
* length
* Integer value that determines the maximum length of the text
* field. If this argument is missing the field should be
* declared to have the longest length allowed by the DBMS.
*
* default
* Text value to be used as default for this field.
*
* notnull
* Boolean flag that indicates whether this field is constrained
* to not be set to null.
*
* @return string DBMS specific SQL code portion that should be used to
* declare the specified field.
*/
abstract public function getNativeDeclaration($field);
/**
* Maps a native array description of a field to a Doctrine datatype and length
*
* @param array $field native field description
* @return array containing the various possible types, length, sign, fixed
*/
abstract public function getPortableDeclaration(array $field);
/**
* Whether the platform prefers sequences for ID generation.
* Subclasses should override this method to return TRUE if they prefer sequences.
*
* @return boolean
*/
public function prefersSequences()
{
return false;
}
/**
* Whether the platform prefers identity columns (eg. autoincrement) for ID generation.
* Subclasses should override this method to return TRUE if they prefer identity columns.
*
* @return boolean
*/
public function prefersIdentityColumns()
{
return false;
}
/**
* Adds a LIMIT/OFFSET clause to the query.
* This default implementation writes the syntax "LIMIT x OFFSET y" to the
* query which is supported by MySql, PostgreSql and Sqlite.
* Any database platforms that do not support this syntax should override
* this implementation and provide their own.
*
* @param string $query The SQL string to write to / append to.
* @param mixed $limit
* @param mixed $offset
*/
public function writeLimitClause($query, $limit = false, $offset = false)
{
$limit = (int) $limit;
$offset = (int) $offset;
if ($limit && $offset) {
$query .= ' LIMIT ' . $limit . ' OFFSET ' . $offset;
} elseif ($limit && ! $offset) {
$query .= ' LIMIT ' . $limit;
} elseif ( ! $limit && $offset) {
$query .= ' LIMIT 999999999999 OFFSET ' . $offset;
}
return $query;
}
/**
* Creates DBMS specific LIMIT/OFFSET SQL for the subqueries that are used in the
* context of the limit-subquery construction.
* This default implementation uses the normal LIMIT/OFFSET creation of the
* platform as provided by {@see modifyLimitQuery()}. This means LIMIT/OFFSET
* in subqueries don't get any special treatment. Most of the time this is not
* sufficient (eg. MySql does not allow LIMIT in subqueries) and the concrete
* platforms should provide their own implementation.
*
* @param string $query The SQL string to write to / append to.
* @return string
* @todo Remove the ORM dependency
*/
public function writeLimitClauseInSubquery(Doctrine_ClassMetadata $rootClass,
$query, $limit = false, $offset = false)
{
return $this->modifyLimitQuery($query, $limit, $offset);
}
/**
* Enter description here...
*
* @param unknown_type $name
* @return unknown
* @todo Remove. Move properties to DatabasePlatform.
*/
public function getProperty($name)
{
if ( ! isset($this->_properties[$name])) {
throw Doctrine_Connection_Exception::unknownProperty($name);
}
return $this->_properties[$name];
}
public function supportsSequences()
{
return false;
}
public function supportsIdentityColumns()
{
return false;
}
public function supportsIndexes()
{
return true;
}
public function supportsTransactions()
{
return true;
}
public function supportsSavepoints()
{
return true;
}
public function supportsPrimaryConstraints()
{
return true;
}
public function supportsForeignKeyConstraints()
{
return true;
}
public function supportsGettingAffectedRows()
{
return true;
}
}
?>