com.jdc.rdb.sql.dml.delete
Class Delete

java.lang.Object
  |
  +--com.jdc.lang.Object
        |
        +--com.jdc.rdb.sql.SQL
              |
              +--com.jdc.rdb.sql.dml.DML
                    |
                    +--com.jdc.rdb.sql.dml.delete.Delete

All Implemented Interfaces:

Serializable, Statement

public class Delete

extends DML

Delete represents a Data Manipulation Language Delete SQL statement. The Delete statement deletes one or more rows from a database Table or View. Deleting a row from a View deletes the row from the Table on which the View is based.

There are two (2) forms of this statement:

• The Searched DELETE form is used to delete one or more rows (optionally determined by a search condition).
• The Positioned DELETE form is used to delete exactly one row (as determined by the current position of a cursor).

Currently, only Delete by a search condition is supported.

Invocation:

This statement can be embedded in an application program or issued through the use of dynamic SQL statements. It is an executable statement that can be dynamically prepared.

Authorization:

To execute this statement, the privileges held by the authorization ID of the statement must include at least one of the following (for IBM® DB2 Universal Database™):

• DELETE privilege on the table or view for which rows are to be deleted.
• CONTROL privilege on the table or view for which rows are to be deleted.
• SYSADM or DBADM authority.

Additionally, to execute a searched Delete statement, the privileges held by the authorization ID of the statement must also include at least one of the following for each table or view referenced by a subquery (for IBM® DB2 Universal Database™):

• SELECT privilege.
• CONTROL privilege.
• SYSADM or DBADM authority.

Example:

        Delete delete = new Delete(table);

        delete.setWhere(column 1 ,  123 );  
        delete.setWhere(column 2 , "Key");  
        . . .

        DeleteStatus status = delete.execute();
 
        if (status.isSuccessful())
        {
            // Delete success
        }
        else
        {
            // Delete failed!
        }

Reference:

IBM® DB2 Universal Database™ SQL Reference Volume 2 Version 8, Pages 497 thru 503.

Note:

Delete from a View is not currently supported.

Version:

2.0

Author:

Jay Damon

See Also:

From, Correlation, Where, With, Serialized Form

Field Summary

static String

COMMAND The Delete statement command keyword.

Fields inherited from class com.jdc.rdb.sql.dml.DML

sql

Fields inherited from class com.jdc.lang.Object

string

Constructor Summary

Delete()
Constructs a new Delete statement object.

Delete(String statement)
Constructs a new Delete statement object for the specified Delete statement.

Delete(Table table)
Constructs a new Delete statement object for the specified Database Table.

Method Summary

DeleteStatus	execute() Executes the Delete statement and returns a DeleteStatus object.
From	getFrom() Returns the From clause for this Delete statement.
Where	getWhere() Returns the Where clause for this Delete statement.
protected boolean	isValid() Returns true if the Delete statement is valid.
Delete	set(DeleteClause clause) Sets a DeleteClause for this Delete statement.
Delete	setWhere(Column column, int value) Sets a search condition for the specified table Column and int value.
Delete	setWhere(Column column, Object value) Sets a search condition for the specified table Column and Object value.
String	toString() Returns a String representation of this Delete statement.

Methods inherited from class com.jdc.rdb.sql.dml.DML

finalize, getColumn, getConnection, getTable, setTable

Methods inherited from class com.jdc.rdb.sql.SQL

addClause, execute, getClause, getCommand, getStatement, setCommand, setConnection, setStatement

Methods inherited from class java.lang.Object

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

Field Detail

COMMAND

public static final String COMMAND

The Delete statement command keyword.

See Also:

Constant Field Values

Constructor Detail

Delete

public Delete()

Constructs a new Delete statement object.

Delete

public Delete(Table table)

Constructs a new Delete statement object for the specified Database Table.

Throws:

SQLInvalidException - No table definition is specified.

Delete

public Delete(String statement)

Constructs a new Delete statement object for the specified Delete statement.

Throws:

SQLInvalidException - No DELETE statement is specified.

Method Detail

execute

public DeleteStatus execute()

Executes the Delete statement and returns a DeleteStatus object.

Returns:

The Delete statement status.

getFrom

public From getFrom()

Returns the From clause for this Delete statement.

Returns:

The Delete statement From clause.

getWhere

public Where getWhere()

Returns the Where clause for this Delete statement.

Returns:

The Delete statement Where clause.

isValid

protected boolean isValid()

Returns true if the Delete statement is valid.

Overrides:

isValid in class SQL

Returns:

This method always returns true.

set

public Delete set(DeleteClause clause)

Sets a DeleteClause for this Delete statement. Use this method to specify a custom Delete clause.

Returns:

This Delete statement object.

Throws:

SQLInvalidException - No DELETE statement clause is specified.

setWhere

public Delete setWhere(Column column,
                       int value)

Sets a search condition for the specified table Column and int value. These values are used to create the Where clause for this statement. A Comparison operator of EQUAL, i.e. "=", is implied.

Returns:

This Delete statement object.

Throws:

SQLInvalidException - No column is specified or an invalid table column is specified.

setWhere

public Delete setWhere(Column column,
                       Object value)

Sets a search condition for the specified table Column and Object value. These values are used to create the Where clause for this statement. A Comparison operator of EQUAL, i.e. "=", is implied.

Returns:

This Delete statement object.

Throws:

SQLInvalidException - No column is specified or an invalid table column is specified.

toString

public String toString()

Returns a String representation of this Delete statement.

Specified by:

toString in interface Statement

Overrides:

toString in class SQL

Returns:

A String representation of this Delete statement.