com.buzzsurf.sql
Class Update

java.lang.Object
  com.buzzsurf.sql.BuzzSQL
      com.buzzsurf.sql.Update

Direct Known Subclasses:

Delete, Insert

public class Update
extends BuzzSQL

An Update object modifies rows in a database and queries the number of rows updated. It is a combination of the underlying JDBC classes;

• java.sql.Connection
• java.sql.PreparedStatement

After execution, you may get the number of rows updated by calling getUpdateCount() or getRowCount().

As an example, the following code fragment creates an Update object using the automatic default connection to the database. The SQL statement is passed via constructor, and the arguments are passed using the setArgs(Object...) method. execute() is called to execute the database call, and then the update count is queries by calling getUpdateCount(). The object is then closed to cleanup any resources and return the connection to the pool.

 Update update = new Update();
 update.setSQL("update example.table_example1 set col_str = ? where col_pk = ?");
 update.setArgs("asdf",1);
 update.execute();
 int updateCount = update.getUpdateCount();
 update.close();
 

Note: This code does not handle exceptions. You normally should wrap your calls in try/catch/finally blocks to handle any problems. It is advisable to put your close() call in a finally block to insure the connection is always released.

Author:

Paul Cowan (www.buzzsurf.com/sql)

See Also:

BuzzSQL

Field Summary

protected int

rowCount

Fields inherited from class com.buzzsurf.sql.BuzzSQL

args, con, DATABASE_FORMATTER, dataSourceName, sql, stmt, usingExplicitConnection

Constructor Summary

Update()
A zero argument constructor is provided for simplified operation with JavBeans, SOAP, and reflection scenarios where having such a constructor is necessary or convenient.

Update(java.lang.String sql)
A single argument constructor that accepts your SQL statement and uses the default DataSource.

Update(java.lang.String sql, java.sql.Connection con)
A dual argument constructor that accepts your SQL statement and a java.sql.Connection object.

Update(java.lang.String sql, java.lang.String dataSourceName)
A dual argument constructor that accepts your SQL statement and the explicit name of a DataSource to use.

Method Summary

Update	execute() During execution a database connection is obtained (if needed), SQL and arguments are merged, and the PreparedStatement is executed against the database.
int	getRowCount() Get the number of rows updated.
int	getUpdateCount() Get the number of rows updated.

Methods inherited from class com.buzzsurf.sql.BuzzSQL

addArgs, close, close, getArgs, getConnection, getDataSourceName, getReleaseInfo, getSQL, getStatement, merge, prepare, queryToString, setArgs, setConnection, setDataSourceName, setSQL, usingExplicitConnection

Methods inherited from class java.lang.Object

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

Field Detail

rowCount

protected int rowCount

Constructor Detail

Update

public Update()

A zero argument constructor is provided for simplified operation with JavBeans, SOAP, and reflection scenarios where having such a constructor is necessary or convenient. At a minimum, you must call setSQL(String) before execution when using this constructor.

Update

public Update(java.lang.String sql)

A single argument constructor that accepts your SQL statement and uses the default DataSource.

Parameters:

sql - The SQL statement

Update

public Update(java.lang.String sql,
              java.lang.String dataSourceName)

A dual argument constructor that accepts your SQL statement and the explicit name of a DataSource to use.

Parameters:

sql - The SQL statement

dataSourceName - The explicit name of the dataSource to obtain a connecton from in DataSourceManager.

Update

public Update(java.lang.String sql,
              java.sql.Connection con)

A dual argument constructor that accepts your SQL statement and a java.sql.Connection object. This constructor provides a great deal of flexibility by allowing the use of "explicit" connections that are supplied by the user rather than being obtained automatically by BuzzSQL. Using a explicit connection also allows BuzzSQL to support database transactions.

Parameters:

sql - The SQL statement

con - The explicit database Connection

Method Detail

getRowCount

public int getRowCount()

Get the number of rows updated.

Returns:

Number of rows updated

getUpdateCount

public int getUpdateCount()

Get the number of rows updated.

Returns:

Number of rows updated

execute

public Update execute()
               throws java.sql.SQLException

During execution a database connection is obtained (if needed), SQL and arguments are merged, and the PreparedStatement is executed against the database. execute() throws an exception if any of these steps fails for any reason.

Typical post-execution steps are slightly different depending on the object subtype. Select based objects will obtain a ResultSet and ResultSetMetaData, while Update based objects will query and save the updated row count to a local variable.

execute() returns a reference to the current object to support method chaining. See Method Chaining for more information. You can assume execution succeeded if no exception is thrown.

Specified by:

execute in class BuzzSQL

Throws:

java.sql.SQLException - if any of the executing JDBC operations failed