Package edu.caltech.nanodb.commands

Class DropTableCommand

java.lang.Object

edu.caltech.nanodb.commands.Command

edu.caltech.nanodb.commands.DropTableCommand

public class DropTableCommand
extends Command

This Command class represents the DROP TABLE SQL command.

Nested Class Summary

Nested classes/interfaces inherited from class edu.caltech.nanodb.commands.Command

Command.Type

Field Summary

Fields

Modifier and Type	Field	Description
private boolean	ifExists	This flag controls whether the drop-table command will fail if the table already doesn't exist when the removal is attempted.
private static org.apache.logging.log4j.Logger	logger	A logging object for reporting anything interesting that happens.
private java.lang.String	tableName	The name of the table to drop from the database.

Fields inherited from class edu.caltech.nanodb.commands.Command

out

Constructor Summary

Constructors

Constructor	Description
DropTableCommand(java.lang.String tableName, boolean ifExists)	Construct a drop-table command for the named table.

Method Summary

Modifier and Type	Method	Description
void	execute(NanoDBServer server)	This method executes the DROP TABLE command by calling the TableManager.dropTable(java.lang.String) method with the specified table name.
boolean	getIfExists()	Returns the value of the "if exists" flag; true indicates that it is not an error if the table doesn't exist when this command is issued.
java.lang.String	getTableName()	Get the name of the table to be dropped.
java.lang.String	toString()

Methods inherited from class edu.caltech.nanodb.commands.Command

getCommandType

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

logger

private static org.apache.logging.log4j.Logger logger

A logging object for reporting anything interesting that happens.

tableName

private java.lang.String tableName

The name of the table to drop from the database.

ifExists

private boolean ifExists

This flag controls whether the drop-table command will fail if the table already doesn't exist when the removal is attempted.

Constructor Detail

DropTableCommand

public DropTableCommand(java.lang.String tableName,
                        boolean ifExists)

Construct a drop-table command for the named table.

Parameters:

tableName - the name of the table to drop.

ifExists - a flag controlling whether the command should complain if the table already doesn't exist when the removal is attempted.

Method Detail

getTableName

public java.lang.String getTableName()

Get the name of the table to be dropped.

Returns:

the name of the table to drop

getIfExists

public boolean getIfExists()

Returns the value of the "if exists" flag; true indicates that it is not an error if the table doesn't exist when this command is issued.

Returns:

the value of the "if exists" flag

execute

public void execute(NanoDBServer server)
             throws ExecutionException

This method executes the DROP TABLE command by calling the TableManager.dropTable(java.lang.String) method with the specified table name.

Specified by:

execute in class Command

Throws:

ExecutionException - if the table doesn't actually exist, or if the table cannot be deleted for some reason.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object