com.jdc.rdb.sql.dml.update
Class Update

java.lang.Object
  |
  +--com.jdc.lang.Object
        |
        +--com.jdc.rdb.sql.SQL
              |
              +--com.jdc.rdb.sql.dml.DML
                    |
                    +--com.jdc.rdb.sql.dml.update.Update

All Implemented Interfaces:

Serializable, Statement

public class Update

extends DML

Update represents a Data Manipulation Language Update SQL statement. The Update statement updates the values of specified columns in rows of a Table table or View. Updating a row of a View updates a row of its base Table.

There are two (2) forms of this statement:

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

Currently, only Update 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™):

• UPDATE privilege on the table or view where rows are to be updated.
• UPDATE privilege on each of the columns to be updated.
• CONTROL privilege on the table or view where rows are to be updated.
• SYSADM or DBADM authority.

Additionally, to execute a searched Update 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:

        Update update = new Update(table);

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

        update.setValue(column 3 , true      );  // boolean Column
        update.setValue(column 4 , 456       );  // int Column
        update.setValue(column 5 , "String"  );  // String Column
        update.setValue(column 6 , new Date());  // Date Column
        . . .

        UpdateStatus status = update.execute();
 
        if (status.isSuccessful())
        {
            // Update success
        }
        else
        {
            // Update failed!
        }

Reference:

IBM® DB2 Universal Database™ SQL Reference Volume 2 Version 8, Pages 738 thru 749.

Note:

Update of a View is not currently supported.

Version:

2.0

Author:

Jay Damon

See Also:

Target, Correlation, Set, Where, With, Serialized Form

Field Summary

static String

COMMAND The Update 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

Update()
Constructs a new Update statement object.

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

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

Method Summary

UpdateStatus	execute() Executes the Update statement and returns an UpdateStatus object.
Set	getSet() Returns the Set clause for this Update statement.
Target	getTarget() Returns the com.jdc.rdb.sql.dml.Target clause for this Update statement.
Where	getWhere() Returns the Where clause for this Update statement.
protected boolean	isValid() Returns true if the Update statement is valid.
Update	set(UpdateClause clause) Sets an UpdateClause for this Update statement.
Update	setValue(Column column, boolean value) Sets a boolean value for the specified Column.
Update	setValue(Column column, int value) Sets an int value for the specified Column.
Update	setValue(Column column, Object value) Sets an Object value for the specified Column.
Update	setWhere(Column column, int value) Sets a search condition for the specified table Column and int value.
Update	setWhere(Column column, Object value) Sets a search condition for the specified table Column and Object value.

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, toString

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 Update statement command keyword.

See Also:

Constant Field Values

Constructor Detail

Update

public Update()

Constructs a new Update statement object.

Update

public Update(Table table)

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

Throws:

SQLInvalidException - No table definition is specified.

Update

public Update(String statement)

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

Throws:

SQLInvalidException - No DELETE statement is specified.

Method Detail

execute

public UpdateStatus execute()

Executes the Update statement and returns an UpdateStatus object.

Returns:

The Update statement status.

getTarget

public Target getTarget()

Returns the com.jdc.rdb.sql.dml.Target clause for this Update statement.

Returns:

The Update statement Target clause.

getSet

public Set getSet()

Returns the Set clause for this Update statement.

Returns:

The Update statement Set clause.

getWhere

public Where getWhere()

Returns the Where clause for this Update statement.

Returns:

The Update statement Where clause.

isValid

protected boolean isValid()

Returns true if the Update statement is valid.

Overrides:

isValid in class SQL

Returns:

True if the SQL statement is valid.
False if the SQL statement is not valid

set

public Update set(UpdateClause clause)

Sets an UpdateClause for this Update statement. Use this method to specify a custom Update clause.

Returns:

This Update statement object.

Throws:

SQLInvalidException - No UPDATE statement clause is specified.

setValue

public Update setValue(Column column,
                       boolean value)

Sets a boolean value for the specified Column. The Column alias is used to create the Columns clause and the boolean value is used to create the Values clause for this Update statement.

Returns:

This Update statement object.

Throws:

SQLInvalidException - No column is specified, an invalid column is specified, or a column for which a value has already been set is specified.

setValue

public Update setValue(Column column,
                       int value)

Sets an int value for the specified Column. The Column alias is used to create the Columns clause and the int value is used to create the Values clause for this Update statement.

Returns:

This Update statement object.

Throws:

SQLInvalidException - No column is specified, an invalid column is specified, or a column for which a value has already been set is specified.

setValue

public Update setValue(Column column,
                       Object value)

Sets an Object value for the specified Column. The Column alias is used to create the Columns clause and the Object value is used to create the Values clause for this Update statement.

Returns:

This Update statement object.

Throws:

SQLInvalidException - No column is specified, an invalid column is specified, or a column for which a value has already been set is specified.

setWhere

public Update setWhere(Column column,
                       int value)

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

Returns:

This Update statement object.

Throws:

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

setWhere

public Update setWhere(Column column,
                       Object value)

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

Returns:

This Update statement object.

Throws:

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