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CMssqlCommandBuilder

Package system.db.schema.mssql
Inheritance class CMssqlCommandBuilder » CDbCommandBuilder » CComponent
Since 1.0.4
Version $Id$
Source Code framework/db/schema/mssql/CMssqlCommandBuilder.php
CMssqlCommandBuilder provides basic methods to create query commands for tables for Mssql Servers.

Public Properties

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PropertyTypeDescriptionDefined By
dbConnection CDbConnection database connection. CDbCommandBuilder
schema CDbSchema the schema for this command builder. CDbCommandBuilder

Public Methods

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MethodDescriptionDefined By
__call() Calls the named method which is not a class method. CComponent
__construct() CDbCommandBuilder
__get() Returns a property value, an event handler list or a behavior based on its name. CComponent
__isset() Checks if a property value is null. CComponent
__set() Sets value of a component property. CComponent
__unset() Sets a component property to be null. CComponent
applyCondition() Alters the SQL to apply WHERE clause. CDbCommandBuilder
applyGroup() Alters the SQL to apply GROUP BY. CDbCommandBuilder
applyHaving() Alters the SQL to apply HAVING. CDbCommandBuilder
applyJoin() Alters the SQL to apply JOIN clause. CDbCommandBuilder
applyLimit() This is a port from Prado Framework. CMssqlCommandBuilder
applyOrder() Alters the SQL to apply ORDER BY. CDbCommandBuilder
asa() Returns the named behavior object. CComponent
attachBehavior() Attaches a behavior to this component. CComponent
attachBehaviors() Attaches a list of behaviors to the component. CComponent
attachEventHandler() Attaches an event handler to an event. CComponent
bindValues() Binds parameter values for an SQL command. CDbCommandBuilder
canGetProperty() Determines whether a property can be read. CComponent
canSetProperty() Determines whether a property can be set. CComponent
createColumnCriteria() Creates a query criteria with the specified column values. CDbCommandBuilder
createCountCommand() Creates a COUNT(*) command for a single table. CMssqlCommandBuilder
createCriteria() Creates a query criteria. CDbCommandBuilder
createDeleteCommand() Creates a DELETE command. CMssqlCommandBuilder
createFindCommand() Creates a SELECT command for a single table. CMssqlCommandBuilder
createInCondition() Generates the expression for selecting rows of specified primary key values. CDbCommandBuilder
createInsertCommand() Creates an INSERT command. CDbCommandBuilder
createPkCondition() Generates the expression for selecting rows of specified primary key values. CDbCommandBuilder
createPkCriteria() Creates a query criteria with the specified primary key. CDbCommandBuilder
createSearchCondition() Generates the expression for searching the specified keywords within a list of columns. CDbCommandBuilder
createSqlCommand() Creates a command based on a given SQL statement. CDbCommandBuilder
createUpdateCommand() Creates an UPDATE command. CMssqlCommandBuilder
createUpdateCounterCommand() Creates an UPDATE command that increments/decrements certain columns. CMssqlCommandBuilder
detachBehavior() Detaches a behavior from the component. CComponent
detachBehaviors() Detaches all behaviors from the component. CComponent
detachEventHandler() Detaches an existing event handler. CComponent
disableBehavior() Disables an attached behavior. CComponent
disableBehaviors() Disables all behaviors attached to this component. CComponent
enableBehavior() Enables an attached behavior. CComponent
enableBehaviors() Enables all behaviors attached to this component. CComponent
getDbConnection() Returns database connection. CDbCommandBuilder
getEventHandlers() Returns the list of attached event handlers for an event. CComponent
getLastInsertID() Returns the last insertion ID for the specified table. CMssqlCommandBuilder
getSchema() Returns the schema for this command builder. CDbCommandBuilder
hasEvent() Determines whether an event is defined. CComponent
hasEventHandler() Checks whether the named event has attached handlers. CComponent
hasProperty() Determines whether a property is defined. CComponent
raiseEvent() Raises an event. CComponent

Protected Methods

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MethodDescriptionDefined By
checkCriteria() Checks if the criteria has an order by clause when using offset/limit. CMssqlCommandBuilder
createCompositeInCondition() Generates the expression for selecting rows with specified composite key values. CDbCommandBuilder
ensureTable() Checks if the parameter is a valid table schema. CDbCommandBuilder
findOrdering() Base on simplified syntax https://msdn2.microsoft.com/en-us/library/aa259187(SQL.80).aspx CMssqlCommandBuilder
joinOrdering() CMssqlCommandBuilder
reverseDirection() CMssqlCommandBuilder
rewriteLimitOffsetSql() Rewrite sql to apply $limit > and $offset > 0 for MSSQL database. CMssqlCommandBuilder

Method Details

applyLimit() method
public string applyLimit(string $sql, integer $limit, integer $offset)
$sql string SQL query string.
$limit integer maximum number of rows, -1 to ignore limit.
$offset integer row offset, -1 to ignore offset.
{return} string SQL with limit and offset.
Source Code: framework/db/schema/mssql/CMssqlCommandBuilder.php#188 (show)
public function applyLimit($sql$limit$offset)
{
    
$limit $limit!==null intval($limit) : -1;
    
$offset $offset!==null intval($offset) : -1;
    if (
$limit && $offset <= 0//just limit
        
$sql preg_replace('/^([\s(])*SELECT( DISTINCT)?(?!\s*TOP\s*\()/i',"\\1SELECT\\2 TOP $limit"$sql);
    else if(
$limit && $offset 0)
        
$sql $this->rewriteLimitOffsetSql($sql$limit,$offset);
    return 
$sql;
}

This is a port from Prado Framework.

Overrides parent implementation. Alters the sql to apply $limit and $offset. The idea for limit with offset is done by modifying the sql on the fly with numerous assumptions on the structure of the sql string. The modification is done with reference to the notes from https://troels.arvin.dk/db/rdbms/#select-limit-offset

SELECT * FROM ( SELECT TOP n * FROM ( SELECT TOP z columns -- (z=n+skip) FROM tablename ORDER BY key ASC ) AS FOO ORDER BY key DESC -- ('FOO' may be anything) ) AS BAR ORDER BY key ASC -- ('BAR' may be anything)

Regular expressions are used to alter the SQL query. The resulting SQL query may be malformed for complex queries. The following restrictions apply

  • In particular, commas should NOT be used as part of the ordering expression or identifier. Commas must only be used for separating the ordering clauses.
  • In the ORDER BY clause, the column name should NOT be be qualified with a table name or view name. Alias the column names or use column index.
  • No clauses should follow the ORDER BY clause, e.g. no COMPUTE or FOR clauses.
  • checkCriteria() method
    protected CDbCrireria checkCriteria(CMssqlTableSchema $table, CDbCriteria $criteria)
    $table CMssqlTableSchema table schema
    $criteria CDbCriteria criteria
    {return} CDbCrireria the modified criteria
    Source Code: framework/db/schema/mssql/CMssqlCommandBuilder.php#296 (show)
    protected function checkCriteria($table$criteria)
    {
        if (
    $criteria->offset && $criteria->order==='')
        {
            
    $criteria->order=is_array($table->primaryKey)?implode(',',$table->primaryKey):$table->primaryKey;
        }
        return 
    $criteria;
    }

    Checks if the criteria has an order by clause when using offset/limit. Override parent implementation to check if an orderby clause if specified when querying with an offset If not, order it by pk.

    createCountCommand() method
    public CDbCommand createCountCommand(CDbTableSchema $table, CDbCriteria $criteria)
    $table CDbTableSchema the table metadata
    $criteria CDbCriteria the query criteria
    {return} CDbCommand query command.
    Source Code: framework/db/schema/mssql/CMssqlCommandBuilder.php#46 (show)
    public function createCountCommand($table,$criteria)
    {
        
    $criteria->order='';
        return 
    parent::createCountCommand($table$criteria);
    }

    Creates a COUNT(*) command for a single table. Override parent implementation to remove the order clause of criteria if it exists

    createDeleteCommand() method
    public CDbCommand createDeleteCommand(CDbTableSchema $table, CDbCriteria $criteria)
    $table CDbTableSchema the table metadata
    $criteria CDbCriteria the query criteria
    {return} CDbCommand delete command.
    Source Code: framework/db/schema/mssql/CMssqlCommandBuilder.php#124 (show)
    public function createDeleteCommand($table,$criteria)
    {
        
    $criteria=$this->checkCriteria($table$criteria);
        return 
    parent::createDeleteCommand($table$criteria);
    }

    Creates a DELETE command. Override parent implementation to check if an orderby clause if specified when querying with an offset

    createFindCommand() method
    public CDbCommand createFindCommand(CDbTableSchema $table, CDbCriteria $criteria)
    $table CDbTableSchema the table metadata
    $criteria CDbCriteria the query criteria
    {return} CDbCommand query command.
    Source Code: framework/db/schema/mssql/CMssqlCommandBuilder.php#59 (show)
    public function createFindCommand($table,$criteria)
    {
        
    $criteria=$this->checkCriteria($table,$criteria);
        return 
    parent::createFindCommand($table,$criteria);

    }

    Creates a SELECT command for a single table. Override parent implementation to check if an orderby clause if specified when querying with an offset

    createUpdateCommand() method
    public CDbCommand createUpdateCommand(CDbTableSchema $table, array $data, CDbCriteria $criteria)
    $table CDbTableSchema the table metadata
    $data array list of columns to be updated (name=>value)
    $criteria CDbCriteria the query criteria
    {return} CDbCommand update command.
    Source Code: framework/db/schema/mssql/CMssqlCommandBuilder.php#74 (show)
    public function createUpdateCommand($table,$data,$criteria)
    {
        
    $criteria=$this->checkCriteria($table,$criteria);
        
    $fields=array();
        
    $values=array();
        
    $bindByPosition=isset($criteria->params[0]);
        
    $i=0;
        foreach(
    $data as $name=>$value)
        {
            if((
    $column=$table->getColumn($name))!==null)
            {
                if (
    $table->sequenceName !== null && $column->isPrimaryKey === true) continue;
                if (
    $column->dbType === 'timestamp') continue;
                if(
    $value instanceof CDbExpression)
                    
    $fields[]=$column->rawName.'='.$value->expression;
                else if(
    $bindByPosition)
                {
                    
    $fields[]=$column->rawName.'=?';
                    
    $values[]=$column->typecast($value);
                }
                else
                {
                    
    $fields[]=$column->rawName.'='.self::PARAM_PREFIX.$i;
                    
    $values[self::PARAM_PREFIX.$i]=$column->typecast($value);
                    
    $i++;
                }
            }
        }
        if(
    $fields===array())
            throw new 
    CDbException(Yii::t('yii','No columns are being updated for table "{table}".',
                array(
    '{table}'=>$table->name)));
        
    $sql="UPDATE {$table->rawName} SET ".implode(', ',$fields);
        
    $sql=$this->applyJoin($sql,$criteria->join);
        
    $sql=$this->applyCondition($sql,$criteria->condition);
        
    $sql=$this->applyOrder($sql,$criteria->order);
        
    $sql=$this->applyLimit($sql,$criteria->limit,$criteria->offset);

        
    $command=$this->getDbConnection()->createCommand($sql);
        
    $this->bindValues($command,array_merge($values,$criteria->params));

        return 
    $command;
    }

    Creates an UPDATE command. Override parent implementation because mssql don't want to update an identity column

    createUpdateCounterCommand() method
    public CDbCommand createUpdateCounterCommand(CDbTableSchema $table, CDbCriteria $counters, array $criteria)
    $table CDbTableSchema the table metadata
    $counters CDbCriteria the query criteria
    $criteria array counters to be updated (counter increments/decrements indexed by column names.)
    {return} CDbCommand the created command
    Source Code: framework/db/schema/mssql/CMssqlCommandBuilder.php#139 (show)
    public function createUpdateCounterCommand($table,$counters,$criteria)
    {
        
    $criteria=$this->checkCriteria($table$criteria);
        return 
    parent::createUpdateCounterCommand($table$counters$criteria);
    }

    Creates an UPDATE command that increments/decrements certain columns. Override parent implementation to check if an orderby clause if specified when querying with an offset

    findOrdering() method
    protected array findOrdering(string $sql)
    $sql string
    {return} array ordering expression as key and ordering direction as value
    Source Code: framework/db/schema/mssql/CMssqlCommandBuilder.php#229 (show)
    protected function findOrdering($sql)
    {
        if(!
    preg_match('/ORDER BY/i'$sql))
            return array();
        
    $matches=array();
        
    $ordering=array();
        
    preg_match_all('/(ORDER BY)[\s"\[](.*)(ASC|DESC)?(?:[\s"\[]|$|COMPUTE|FOR)/i'$sql$matches);
        if(
    count($matches)>&& count($matches[2]) > 0)
        {
            
    $parts explode(','$matches[2][0]);
            foreach(
    $parts as $part)
            {
                
    $subs=array();
                if(
    preg_match_all('/(.*)[\s"\]](ASC|DESC)$/i'trim($part), $subs))
                {
                    if(
    count($subs) > && count($subs[2]) > 0)
                    {
                        
    $ordering[$subs[1][0]] = $subs[2][0];
                    }
                    
    //else what?
                
    }
                else
                    
    $ordering[trim($part)] = 'ASC';
            }
        }
        return 
    $ordering;
    }

    Base on simplified syntax https://msdn2.microsoft.com/en-us/library/aa259187(SQL.80).aspx

    getLastInsertID() method
    public mixed getLastInsertID(CDbTableSchema $table)
    $table CDbTableSchema the table metadata
    {return} mixed last insertion id. Null is returned if no sequence name.
    Source Code: framework/db/schema/mssql/CMssqlCommandBuilder.php#31 (show)
    public function getLastInsertID($table)
    {
        if(
    $table->sequenceName!==null)
            return 
    $this->getDbConnection()->createCommand('SELECT SCOPE_IDENTITY()')->queryScalar();
        else
            return 
    null;
    }

    Returns the last insertion ID for the specified table. Override parent implemantation since PDO mssql driver does not provide this method

    joinOrdering() method
    protected string joinOrdering(array $orders)
    $orders array ordering obtained from findOrdering()
    {return} string concat the orderings
    Source Code: framework/db/schema/mssql/CMssqlCommandBuilder.php#263 (show)
    protected function joinOrdering($orders)
    {
        if(
    count($orders)>0)
        {
            
    $str=array();
            foreach(
    $orders as $column => $direction)
                
    $str[] = $column.' '.$direction;
            return 
    'ORDER BY '.implode(', '$str);
        }
    }

    reverseDirection() method
    protected array reverseDirection(array $orders)
    $orders array original ordering
    {return} array ordering with reversed direction.
    Source Code: framework/db/schema/mssql/CMssqlCommandBuilder.php#280 (show)
    protected function reverseDirection($orders)
    {
        foreach(
    $orders as $column => $direction)
            
    $orders[$column] = strtolower(trim($direction))==='desc' 'ASC' 'DESC';
        return 
    $orders;
    }

    rewriteLimitOffsetSql() method
    protected sql rewriteLimitOffsetSql(string $sql, integer $limit, integer $offset)
    $sql string sql query
    $limit integer > 0
    $offset integer > 0
    {return} sql modified sql query applied with limit and offset.
    Source Code: framework/db/schema/mssql/CMssqlCommandBuilder.php#209 (show)
    protected function rewriteLimitOffsetSql($sql$limit$offset)
    {
        
    $fetch $limit+$offset;
        
    $sql preg_replace('/^([\s(])*SELECT( DISTINCT)?(?!\s*TOP\s*\()/i',"\\1SELECT\\2 TOP $fetch"$sql);
        
    $ordering $this->findOrdering($sql);

        
    $orginalOrdering $this->joinOrdering($ordering);
        
    $reverseOrdering $this->joinOrdering($this->reverseDirection($ordering));
        
    $sql "SELECT * FROM (SELECT TOP {$limit} * FROM ($sql) as [__inner top table__] {$reverseOrdering}) as [__outer top table__] {$orginalOrdering}";
        return 
    $sql;
    }

    Rewrite sql to apply $limit > and $offset > 0 for MSSQL database. See https://troels.arvin.dk/db/rdbms/#select-limit-offset