CDbSchema
包 | system.db.schema |
---|---|
继承 | abstract class CDbSchema » CComponent |
子类 | CCubridSchema, CMssqlSchema, CMysqlSchema, COciSchema, CPgsqlSchema, CSqliteSchema |
可用自 | 1.0 |
源码 | framework/db/schema/CDbSchema.php |
公共属性
属性 | 类型 | 描述 | 被定义在 |
---|---|---|---|
columnTypes | array | the abstract column types mapped to physical column types. | CDbSchema |
commandBuilder | CDbCommandBuilder | the SQL command builder for this connection. | CDbSchema |
dbConnection | CDbConnection | database connection. | CDbSchema |
tableNames | array | Returns all table names in the database. | CDbSchema |
tables | array | Returns the metadata for all tables in the database. | CDbSchema |
公共方法
方法 | 描述 | 被定义在 |
---|---|---|
__call() | Calls the named method which is not a class method. | CComponent |
__construct() | Constructor. | CDbSchema |
__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 |
addColumn() | Builds a SQL statement for adding a new DB column. | CDbSchema |
addForeignKey() | Builds a SQL statement for adding a foreign key constraint to an existing table. | CDbSchema |
addPrimaryKey() | Builds a SQL statement for adding a primary key constraint to an existing table. | CDbSchema |
alterColumn() | Builds a SQL statement for changing the definition of a column. | CDbSchema |
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 |
canGetProperty() | Determines whether a property can be read. | CComponent |
canSetProperty() | Determines whether a property can be set. | CComponent |
checkIntegrity() | Enables or disables integrity check. | CDbSchema |
compareTableNames() | Compares two table names. | CDbSchema |
createIndex() | Builds a SQL statement for creating a new index. | CDbSchema |
createTable() | Builds a SQL statement for creating a new DB table. | CDbSchema |
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 |
dropColumn() | Builds a SQL statement for dropping a DB column. | CDbSchema |
dropForeignKey() | Builds a SQL statement for dropping a foreign key constraint. | CDbSchema |
dropIndex() | Builds a SQL statement for dropping an index. | CDbSchema |
dropPrimaryKey() | Builds a SQL statement for removing a primary key constraint to an existing table. | CDbSchema |
dropTable() | Builds a SQL statement for dropping a DB table. | CDbSchema |
enableBehavior() | Enables an attached behavior. | CComponent |
enableBehaviors() | Enables all behaviors attached to this component. | CComponent |
evaluateExpression() | Evaluates a PHP expression or callback under the context of this component. | CComponent |
getColumnType() | Converts an abstract column type into a physical column type. | CDbSchema |
getCommandBuilder() | Returns the SQL command builder for this connection. | CDbSchema |
getDbConnection() | Returns database connection. The connection is active. | CDbSchema |
getEventHandlers() | Returns the list of attached event handlers for an event. | CComponent |
getTable() | Obtains the metadata for the named table. | CDbSchema |
getTableNames() | Returns all table names in the database. | CDbSchema |
getTables() | Returns the metadata for all tables in the database. | CDbSchema |
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 |
quoteColumnName() | Quotes a column name for use in a query. | CDbSchema |
quoteSimpleColumnName() | Quotes a simple column name for use in a query. | CDbSchema |
quoteSimpleTableName() | Quotes a simple table name for use in a query. | CDbSchema |
quoteTableName() | Quotes a table name for use in a query. | CDbSchema |
raiseEvent() | Raises an event. | CComponent |
refresh() | Refreshes the schema. | CDbSchema |
renameColumn() | Builds a SQL statement for renaming a column. | CDbSchema |
renameTable() | Builds a SQL statement for renaming a DB table. | CDbSchema |
resetSequence() | Resets the sequence value of a table's primary key. | CDbSchema |
truncateTable() | Builds a SQL statement for truncating a DB table. | CDbSchema |
受保护的方法
方法 | 描述 | 被定义在 |
---|---|---|
createCommandBuilder() | Creates a command builder for the database. | CDbSchema |
findTableNames() | Returns all table names in the database. | CDbSchema |
loadTable() | Loads the metadata for the specified table. | CDbSchema |
属性详情
the abstract column types mapped to physical column types.
the SQL command builder for this connection.
database connection. The connection is active.
Returns all table names in the database.
Returns the metadata for all tables in the database.
方法详情
public void __construct(CDbConnection $conn)
| ||
$conn | CDbConnection | database connection. |
public function __construct($conn)
{
$this->_connection=$conn;
foreach($conn->schemaCachingExclude as $name)
$this->_cacheExclude[$name]=true;
}
Constructor.
public string addColumn(string $table, string $column, string $type)
| ||
$table | string | the table that the new column will be added to. The table name will be properly quoted by the method. |
$column | string | the name of the new column. The name will be properly quoted by the method. |
$type | string | the column type. The getColumnType method will be invoked to convert abstract column type (if any) into the physical one. Anything that is not recognized as abstract type will be kept in the generated SQL. For example, 'string' will be turned into 'varchar(255)', while 'string not null' will become 'varchar(255) not null'. |
{return} | string | the SQL statement for adding a new column. |
public function addColumn($table,$column,$type)
{
return 'ALTER TABLE ' . $this->quoteTableName($table)
. ' ADD ' . $this->quoteColumnName($column) . ' '
. $this->getColumnType($type);
}
Builds a SQL statement for adding a new DB column.
public string addForeignKey(string $name, string $table, string|array $columns, string $refTable, string|array $refColumns, string $delete=NULL, string $update=NULL)
| ||
$name | string | the name of the foreign key constraint. |
$table | string | the table that the foreign key constraint will be added to. |
$columns | string|array | the name of the column to that the constraint will be added on. If there are multiple columns, separate them with commas or pass as an array of column names. |
$refTable | string | the table that the foreign key references to. |
$refColumns | string|array | the name of the column that the foreign key references to. If there are multiple columns, separate them with commas or pass as an array of column names. |
$delete | string | the ON DELETE option. Most DBMS support these options: RESTRICT, CASCADE, NO ACTION, SET DEFAULT, SET NULL |
$update | string | the ON UPDATE option. Most DBMS support these options: RESTRICT, CASCADE, NO ACTION, SET DEFAULT, SET NULL |
{return} | string | the SQL statement for adding a foreign key constraint to an existing table. |
public function addForeignKey($name,$table,$columns,$refTable,$refColumns,$delete=null,$update=null)
{
if(is_string($columns))
$columns=preg_split('/\s*,\s*/',$columns,-1,PREG_SPLIT_NO_EMPTY);
foreach($columns as $i=>$col)
$columns[$i]=$this->quoteColumnName($col);
if(is_string($refColumns))
$refColumns=preg_split('/\s*,\s*/',$refColumns,-1,PREG_SPLIT_NO_EMPTY);
foreach($refColumns as $i=>$col)
$refColumns[$i]=$this->quoteColumnName($col);
$sql='ALTER TABLE '.$this->quoteTableName($table)
.' ADD CONSTRAINT '.$this->quoteColumnName($name)
.' FOREIGN KEY ('.implode(', ',$columns).')'
.' REFERENCES '.$this->quoteTableName($refTable)
.' ('.implode(', ',$refColumns).')';
if($delete!==null)
$sql.=' ON DELETE '.$delete;
if($update!==null)
$sql.=' ON UPDATE '.$update;
return $sql;
}
Builds a SQL statement for adding a foreign key constraint to an existing table. The method will properly quote the table and column names.
public string addPrimaryKey(string $name, string $table, string|array $columns)
| ||
$name | string | the name of the primary key constraint. |
$table | string | the table that the primary key constraint will be added to. |
$columns | string|array | comma separated string or array of columns that the primary key will consist of. Array value can be passed since 1.1.14. |
{return} | string | the SQL statement for adding a primary key constraint to an existing table. |
public function addPrimaryKey($name,$table,$columns)
{
if(is_string($columns))
$columns=preg_split('/\s*,\s*/',$columns,-1,PREG_SPLIT_NO_EMPTY);
foreach($columns as $i=>$col)
$columns[$i]=$this->quoteColumnName($col);
return 'ALTER TABLE ' . $this->quoteTableName($table) . ' ADD CONSTRAINT '
. $this->quoteColumnName($name) . ' PRIMARY KEY ('
. implode(', ',$columns). ' )';
}
Builds a SQL statement for adding a primary key constraint to an existing table.
public string alterColumn(string $table, string $column, string $type)
| ||
$table | string | the table whose column is to be changed. The table name will be properly quoted by the method. |
$column | string | the name of the column to be changed. The name will be properly quoted by the method. |
$type | string | the new column type. The getColumnType method will be invoked to convert abstract column type (if any) into the physical one. Anything that is not recognized as abstract type will be kept in the generated SQL. For example, 'string' will be turned into 'varchar(255)', while 'string not null' will become 'varchar(255) not null'. |
{return} | string | the SQL statement for changing the definition of a column. |
public function alterColumn($table,$column,$type)
{
return 'ALTER TABLE ' . $this->quoteTableName($table) . ' CHANGE '
. $this->quoteColumnName($column) . ' '
. $this->quoteColumnName($column) . ' '
. $this->getColumnType($type);
}
Builds a SQL statement for changing the definition of a column.
public void checkIntegrity(boolean $check=true, string $schema='')
| ||
$check | boolean | whether to turn on or off the integrity check. |
$schema | string | the schema of the tables. Defaults to empty string, meaning the current or default schema. |
public function checkIntegrity($check=true,$schema='')
{
}
Enables or disables integrity check.
public boolean compareTableNames(string $name1, string $name2)
| ||
$name1 | string | table name 1 |
$name2 | string | table name 2 |
{return} | boolean | whether the two table names refer to the same table. |
public function compareTableNames($name1,$name2)
{
$name1=str_replace(array('"','`',"'"),'',$name1);
$name2=str_replace(array('"','`',"'"),'',$name2);
if(($pos=strrpos($name1,'.'))!==false)
$name1=substr($name1,$pos+1);
if(($pos=strrpos($name2,'.'))!==false)
$name2=substr($name2,$pos+1);
if($this->_connection->tablePrefix!==null)
{
if(strpos($name1,'{')!==false)
$name1=$this->_connection->tablePrefix.str_replace(array('{','}'),'',$name1);
if(strpos($name2,'{')!==false)
$name2=$this->_connection->tablePrefix.str_replace(array('{','}'),'',$name2);
}
return $name1===$name2;
}
Compares two table names. The table names can be either quoted or unquoted. This method will consider both cases.
protected CDbCommandBuilder createCommandBuilder()
| ||
{return} | CDbCommandBuilder | command builder instance |
protected function createCommandBuilder()
{
return new CDbCommandBuilder($this);
}
Creates a command builder for the database. This method may be overridden by child classes to create a DBMS-specific command builder.
public string createIndex(string $name, string $table, string|array $columns, boolean $unique=false)
| ||
$name | string | the name of the index. The name will be properly quoted by the method. |
$table | string | the table that the new index will be created for. The table name will be properly quoted by the method. |
$columns | string|array | the column(s) that should be included in the index. If there are multiple columns, please separate them by commas or pass as an array of column names. Each column name will be properly quoted by the method, unless a parenthesis is found in the name. |
$unique | boolean | whether to add UNIQUE constraint on the created index. |
{return} | string | the SQL statement for creating a new index. |
public function createIndex($name,$table,$columns,$unique=false)
{
$cols=array();
if(is_string($columns))
$columns=preg_split('/\s*,\s*/',$columns,-1,PREG_SPLIT_NO_EMPTY);
foreach($columns as $col)
{
if(strpos($col,'(')!==false)
$cols[]=$col;
else
$cols[]=$this->quoteColumnName($col);
}
return ($unique ? 'CREATE UNIQUE INDEX ' : 'CREATE INDEX ')
. $this->quoteTableName($name).' ON '
. $this->quoteTableName($table).' ('.implode(', ',$cols).')';
}
Builds a SQL statement for creating a new index.
public string createTable(string $table, array $columns, string $options=NULL)
| ||
$table | string | the name of the table to be created. The name will be properly quoted by the method. |
$columns | array | the columns (name=>definition) in the new table. |
$options | string | additional SQL fragment that will be appended to the generated SQL. |
{return} | string | the SQL statement for creating a new DB table. |
public function createTable($table,$columns,$options=null)
{
$cols=array();
foreach($columns as $name=>$type)
{
if(is_string($name))
$cols[]="\t".$this->quoteColumnName($name).' '.$this->getColumnType($type);
else
$cols[]="\t".$type;
}
$sql="CREATE TABLE ".$this->quoteTableName($table)." (\n".implode(",\n",$cols)."\n)";
return $options===null ? $sql : $sql.' '.$options;
}
Builds a SQL statement for creating a new DB table.
The columns in the new table should be specified as name-definition pairs (e.g. 'name'=>'string'),
where name stands for a column name which will be properly quoted by the method, and definition
stands for the column type which can contain an abstract DB type.
The getColumnType method will be invoked to convert any abstract type into a physical one.
If a column is specified with definition only (e.g. 'PRIMARY KEY (name, type)'), it will be directly
inserted into the generated SQL.
public string dropColumn(string $table, string $column)
| ||
$table | string | the table whose column is to be dropped. The name will be properly quoted by the method. |
$column | string | the name of the column to be dropped. The name will be properly quoted by the method. |
{return} | string | the SQL statement for dropping a DB column. |
public function dropColumn($table,$column)
{
return "ALTER TABLE ".$this->quoteTableName($table)
." DROP COLUMN ".$this->quoteColumnName($column);
}
Builds a SQL statement for dropping a DB column.
public string dropForeignKey(string $name, string $table)
| ||
$name | string | the name of the foreign key constraint to be dropped. The name will be properly quoted by the method. |
$table | string | the table whose foreign is to be dropped. The name will be properly quoted by the method. |
{return} | string | the SQL statement for dropping a foreign key constraint. |
public function dropForeignKey($name,$table)
{
return 'ALTER TABLE '.$this->quoteTableName($table)
.' DROP CONSTRAINT '.$this->quoteColumnName($name);
}
Builds a SQL statement for dropping a foreign key constraint.
public string dropIndex(string $name, string $table)
| ||
$name | string | the name of the index to be dropped. The name will be properly quoted by the method. |
$table | string | the table whose index is to be dropped. The name will be properly quoted by the method. |
{return} | string | the SQL statement for dropping an index. |
public function dropIndex($name,$table)
{
return 'DROP INDEX '.$this->quoteTableName($name).' ON '.$this->quoteTableName($table);
}
Builds a SQL statement for dropping an index.
public string dropPrimaryKey(string $name, string $table)
| ||
$name | string | the name of the primary key constraint to be removed. |
$table | string | the table that the primary key constraint will be removed from. |
{return} | string | the SQL statement for removing a primary key constraint from an existing table. |
public function dropPrimaryKey($name,$table)
{
return 'ALTER TABLE ' . $this->quoteTableName($table) . ' DROP CONSTRAINT '
. $this->quoteColumnName($name);
}
Builds a SQL statement for removing a primary key constraint to an existing table.
public string dropTable(string $table)
| ||
$table | string | the table to be dropped. The name will be properly quoted by the method. |
{return} | string | the SQL statement for dropping a DB table. |
public function dropTable($table)
{
return "DROP TABLE ".$this->quoteTableName($table);
}
Builds a SQL statement for dropping a DB table.
protected array findTableNames(string $schema='')
| ||
$schema | string | the schema of the tables. Defaults to empty string, meaning the current or default schema. If not empty, the returned table names will be prefixed with the schema name. |
{return} | array | all table names in the database. |
protected function findTableNames($schema='')
{
throw new CDbException(Yii::t('yii','{class} does not support fetching all table names.',
array('{class}'=>get_class($this))));
}
Returns all table names in the database. This method should be overridden by child classes in order to support this feature because the default implementation simply throws an exception.
public string getColumnType(string $type)
| ||
$type | string | abstract column type |
{return} | string | physical column type. |
public function getColumnType($type)
{
if(isset($this->columnTypes[$type]))
return $this->columnTypes[$type];
elseif(($pos=strpos($type,' '))!==false)
{
$t=substr($type,0,$pos);
return (isset($this->columnTypes[$t]) ? $this->columnTypes[$t] : $t).substr($type,$pos);
}
else
return $type;
}
Converts an abstract column type into a physical column type. The conversion is done using the type map specified in columnTypes. These abstract column types are supported (using MySQL as example to explain the corresponding physical types):
- pk and bigpk: an auto-incremental primary key type, will be converted into "int(11) NOT NULL AUTO_INCREMENT PRIMARY KEY" or "bigint(20) NOT NULL AUTO_INCREMENT PRIMARY KEY"
- string: string type, will be converted into "varchar(255)"
- text: a long string type, will be converted into "text"
- integer: integer type, will be converted into "int(11)"
- bigint: integer type, will be converted into "bigint(20)"
- boolean: boolean type, will be converted into "tinyint(1)"
- float: float number type, will be converted into "float"
- decimal: decimal number type, will be converted into "decimal"
- datetime: datetime type, will be converted into "datetime"
- timestamp: timestamp type, will be converted into "timestamp"
- time: time type, will be converted into "time"
- date: date type, will be converted into "date"
- binary: binary data type, will be converted into "blob"
If the abstract type contains two or more parts separated by spaces (e.g. "string NOT NULL"), then only the first part will be converted, and the rest of the parts will be appended to the conversion result. For example, 'string NOT NULL' is converted to 'varchar(255) NOT NULL'.
public CDbCommandBuilder getCommandBuilder()
| ||
{return} | CDbCommandBuilder | the SQL command builder for this connection. |
public function getCommandBuilder()
{
if($this->_builder!==null)
return $this->_builder;
else
return $this->_builder=$this->createCommandBuilder();
}
public CDbConnection getDbConnection()
| ||
{return} | CDbConnection | database connection. The connection is active. |
public function getDbConnection()
{
return $this->_connection;
}
public CDbTableSchema getTable(string $name, boolean $refresh=false)
| ||
$name | string | table name |
$refresh | boolean | if we need to refresh schema cache for a table. Parameter available since 1.1.9 |
{return} | CDbTableSchema | table metadata. Null if the named table does not exist. |
public function getTable($name,$refresh=false)
{
if($refresh===false && isset($this->_tables[$name]))
return $this->_tables[$name];
else
{
if($this->_connection->tablePrefix!==null && strpos($name,'{{')!==false)
$realName=preg_replace('/\{\{(.*?)\}\}/',$this->_connection->tablePrefix.'$1',$name);
else
$realName=$name;
// temporarily disable query caching
if($this->_connection->queryCachingDuration>0)
{
$qcDuration=$this->_connection->queryCachingDuration;
$this->_connection->queryCachingDuration=0;
}
if(!isset($this->_cacheExclude[$name]) && ($duration=$this->_connection->schemaCachingDuration)>0 && $this->_connection->schemaCacheID!==false && ($cache=Yii::app()->getComponent($this->_connection->schemaCacheID))!==null)
{
$key='yii:dbschema'.$this->_connection->connectionString.':'.$this->_connection->username.':'.$name;
$table=$cache->get($key);
if($refresh===true || $table===false)
{
$table=$this->loadTable($realName);
if($table!==null)
$cache->set($key,$table,$duration);
}
$this->_tables[$name]=$table;
}
else
$this->_tables[$name]=$table=$this->loadTable($realName);
if(isset($qcDuration)) // re-enable query caching
$this->_connection->queryCachingDuration=$qcDuration;
return $table;
}
}
Obtains the metadata for the named table.
public array getTableNames(string $schema='')
| ||
$schema | string | the schema of the tables. Defaults to empty string, meaning the current or default schema. If not empty, the returned table names will be prefixed with the schema name. |
{return} | array | all table names in the database. |
public function getTableNames($schema='')
{
if(!isset($this->_tableNames[$schema]))
$this->_tableNames[$schema]=$this->findTableNames($schema);
return $this->_tableNames[$schema];
}
Returns all table names in the database.
public array getTables(string $schema='')
| ||
$schema | string | the schema of the tables. Defaults to empty string, meaning the current or default schema. |
{return} | array | the metadata for all tables in the database. Each array element is an instance of CDbTableSchema (or its child class). The array keys are table names. |
public function getTables($schema='')
{
$tables=array();
foreach($this->getTableNames($schema) as $name)
{
if(($table=$this->getTable($name))!==null)
$tables[$name]=$table;
}
return $tables;
}
Returns the metadata for all tables in the database.
abstract protected CDbTableSchema loadTable(string $name)
| ||
$name | string | table name |
{return} | CDbTableSchema | driver dependent table metadata, null if the table does not exist. |
Loads the metadata for the specified table.
public string quoteColumnName(string $name)
| ||
$name | string | column name |
{return} | string | the properly quoted column name |
public function quoteColumnName($name)
{
if(($pos=strrpos($name,'.'))!==false)
{
$prefix=$this->quoteTableName(substr($name,0,$pos)).'.';
$name=substr($name,$pos+1);
}
else
$prefix='';
return $prefix . ($name==='*' ? $name : $this->quoteSimpleColumnName($name));
}
Quotes a column name for use in a query. If the column name contains prefix, the prefix will also be properly quoted.
public string quoteSimpleColumnName(string $name)
| ||
$name | string | column name |
{return} | string | the properly quoted column name |
public function quoteSimpleColumnName($name)
{
return '"'.$name.'"';
}
Quotes a simple column name for use in a query. A simple column name does not contain prefix.
public string quoteSimpleTableName(string $name)
| ||
$name | string | table name |
{return} | string | the properly quoted table name |
public function quoteSimpleTableName($name)
{
return "'".$name."'";
}
Quotes a simple table name for use in a query. A simple table name does not schema prefix.
public string quoteTableName(string $name)
| ||
$name | string | table name |
{return} | string | the properly quoted table name |
public function quoteTableName($name)
{
if(strpos($name,'.')===false)
return $this->quoteSimpleTableName($name);
$parts=explode('.',$name);
foreach($parts as $i=>$part)
$parts[$i]=$this->quoteSimpleTableName($part);
return implode('.',$parts);
}
Quotes a table name for use in a query. If the table name contains schema prefix, the prefix will also be properly quoted.
public void refresh()
|
public function refresh()
{
if(($duration=$this->_connection->schemaCachingDuration)>0 && $this->_connection->schemaCacheID!==false && ($cache=Yii::app()->getComponent($this->_connection->schemaCacheID))!==null)
{
foreach(array_keys($this->_tables) as $name)
{
if(!isset($this->_cacheExclude[$name]))
{
$key='yii:dbschema'.$this->_connection->connectionString.':'.$this->_connection->username.':'.$name;
$cache->delete($key);
}
}
}
$this->_tables=array();
$this->_tableNames=array();
$this->_builder=null;
}
Refreshes the schema. This method resets the loaded table metadata and command builder so that they can be recreated to reflect the change of schema.
public string renameColumn(string $table, string $name, string $newName)
| ||
$table | string | the table whose column is to be renamed. The name will be properly quoted by the method. |
$name | string | the old name of the column. The name will be properly quoted by the method. |
$newName | string | the new name of the column. The name will be properly quoted by the method. |
{return} | string | the SQL statement for renaming a DB column. |
public function renameColumn($table,$name,$newName)
{
return "ALTER TABLE ".$this->quoteTableName($table)
. " RENAME COLUMN ".$this->quoteColumnName($name)
. " TO ".$this->quoteColumnName($newName);
}
Builds a SQL statement for renaming a column.
public string renameTable(string $table, string $newName)
| ||
$table | string | the table to be renamed. The name will be properly quoted by the method. |
$newName | string | the new table name. The name will be properly quoted by the method. |
{return} | string | the SQL statement for renaming a DB table. |
public function renameTable($table,$newName)
{
return 'RENAME TABLE ' . $this->quoteTableName($table) . ' TO ' . $this->quoteTableName($newName);
}
Builds a SQL statement for renaming a DB table.
public void resetSequence(CDbTableSchema $table, integer|null $value=NULL)
| ||
$table | CDbTableSchema | the table schema whose primary key sequence will be reset |
$value | integer|null | the value for the primary key of the next new row inserted. If this is not set, the next new row's primary key will have the max value of a primary key plus one (i.e. sequence trimming). |
Resets the sequence value of a table's primary key. The sequence will be reset such that the primary key of the next new row inserted will have the specified value or max value of a primary key plus one (i.e. sequence trimming).
public string truncateTable(string $table)
| ||
$table | string | the table to be truncated. The name will be properly quoted by the method. |
{return} | string | the SQL statement for truncating a DB table. |
public function truncateTable($table)
{
return "TRUNCATE TABLE ".$this->quoteTableName($table);
}
Builds a SQL statement for truncating a DB table.