DatabaseEnvironment (Denodo Virtual DataPort 6.0.16 API)

```
public interface DatabaseEnvironment
```
Interface which defines utility methods accessible from the stored procedures, and used to communicate with the VDP server: obtains database properties, logging, query execution, procedure and function lookup...
For the methods executeQuery and executeUpdate that support parameters (the ones that have the parameter Object[] parameterValues), take the following into account:
- When you execute them, the Server replaces the placeholders ("?") of the query with the values of the parameters. Then, it executes the query.
- The benefit of using these methods is that you do not need to know how to format the parameters. With integers and string is easy, but it is more complex with dates. It is easier to pass the parameters as objects and let the Server process them appropriately.
- The number of elements in the array parameterValues has to match the number of "?" in the query.
- Do not surround the placeholders with single quotes, even if the value is a text.
  For example, SELECT * FROM customer WHERE last_name = ?
  The Virtual DataPort server will format each value depending on the class of the object:
  - If the object is a number (java.lang.Double, java.lang.Integer, etc.), it replaces the placeholder with the number, without quotes.
  - If the object is a java.lang.String, it surrounds the value with single quotes.
  - If the object is one of the following, the Server replaces the placeholder with TO_DATE( <property "datepattern" of the i18n of the Server> , <string that represents the date object converted using the "datepattern" of the i18n of the Server> )
    - java.sql.Date
    - java.util.Date
    - java.sql.Timestamp
    - java.util.Calendar

Method Summary

Methods
Modifier and Type	Method and Description
`Transaction`	`createTransaction()` Creates a new transaction.
`ResultSet`	`executeQuery(String query)` Executes a query against the VDP server.
`ResultSet`	`executeQuery(String query, long queryTimeout, long chunkTimeout, long chunkSize)` Executes a query against the VDP server.
`ResultSet`	`executeQuery(String query, Object[] parameterValues)` Executes a parameterized query.
`ResultSet`	`executeQuery(String query, Object[] parameterValues, long queryTimeout, long chunkTimeout, long chunkSize)` Executes a parameterized query specifying the timeouts.
`int`	`executeUpdate(String query)` Executes an INSERT, UPDATE or DELETE query.
`int`	`executeUpdate(String query, Object[] parameterValues)` Executes a parameterized INSERT, UPDATE or DELETE query.
`int`	`executeUpdate(String query, Object[] parameterValues, long queryTimeout)` Executes a parameterized INSERT, UPDATE or DELETE query specifying the timeouts.
`String`	`executeVqlCommand(String command)` Executes a VQL command.
`String`	`executeVqlCommand(String command, long queryTimeout)` Executes a VQL command with a timeout.
`String`	`executeVqlCommand(String databaseName, String command)` Executes a VQL command over the given database.
`String`	`executeVqlCommand(String databaseName, String command, long queryTimeout)` Executes a VQL command over the given database with a timeout.
`String`	`getDatabaseProperty(String name)` Obtains a database property.
`void`	`joinTransaction(StoredProcedure storedProcedure)` Joins a stored procedure to the current transaction.
`void`	`log(int level, String logMessage)` Adds an entry log, with the specified level.
`DatabaseFunction`	`lookupFunction(String functionName, int arity)` Obtains a handler to execute a function.
`StoredProcedureExecutor`	`lookupProcedure(String procedureName)` Obtains a stored procedure reference, which can be used to execute it.

- Method Detail
  - executeQuery
```
ResultSet executeQuery(String query)
                       throws StoredProcedureException
```
    Executes a query against the VDP server.
    
    Parameters:
    query - the VQL query.
    
    Returns:
    a JDBC ResultSet.
    
    Throws:
    
    StoredProcedureException - if there is some error executing the query.
  - executeQuery
```
ResultSet executeQuery(String query,
                     long queryTimeout,
                     long chunkTimeout,
                     long chunkSize)
                       throws StoredProcedureException
```
    Executes a query against the VDP server.
    
    Parameters:
    query - the VQL query.
    queryTimeout - query timeout configuration.
    chunkTimeout - chunk timeout configuration.
    chunkSize - chunk size configuration.
    
    Returns:
    a JDBC ResultSet.
    
    Throws:
    
    StoredProcedureException - if there is some error executing the query.
  - executeQuery
```
ResultSet executeQuery(String query,
                     Object[] parameterValues)
                       throws StoredProcedureException
```
    Executes a parameterized query.
    
    Parameters:
    query - a VQL query that may contain one or more '?' parameter placeholders
    parameterValues - the list of values to be replaced in the query. The number of elements in this array has to match the number of "?" in the query.
    
    Returns:
    a JDBC ResultSet.
    
    Throws:
    
    StoredProcedureException - if there is some error executing the query, or the parameters supplied are invalid.
  - executeQuery
```
ResultSet executeQuery(String query,
                     Object[] parameterValues,
                     long queryTimeout,
                     long chunkTimeout,
                     long chunkSize)
                       throws StoredProcedureException
```
    Executes a parameterized query specifying the timeouts.
    
    Parameters:
    query - a VQL query that may contain one or more '?' parameter placeholders
    parameterValues - the list of values to be replaced in the query. The number of elements in this array has to match the number of "?" in the query.
    queryTimeout - query timeout configuration.
    chunkTimeout - chunk timeout configuration.
    chunkSize - chunk size configuration.
    
    Returns:
    a JDBC ResultSet.
    
    Throws:
    
    StoredProcedureException - if there is some error executing the query, or the parameters supplied are invalid.
  - lookupProcedure
```
StoredProcedureExecutor lookupProcedure(String procedureName)
                                        throws com.denodo.vdb.util.SynchronizeException,
                                               StoredProcedureException
```
    Obtains a stored procedure reference, which can be used to execute it.
    
    Parameters:
    procedureName - the name of the stored procedure.
    
    Returns:
    the a reference to the stored procedure.
    
    Throws:
    
    com.denodo.vdb.util.SynchronizeException
    
    StoredProcedureException - if there is some error obtaining the procedure.
  - lookupFunction
```
DatabaseFunction lookupFunction(String functionName,
                              int arity)
                                throws StoredProcedureException
```
    Obtains a handler to execute a function.
    
    Parameters:
    functionName - the name of the function.
    arity - the arity of the function.
    
    Returns:
    a function handler.
    
    Throws:
    
    StoredProcedureException - if there is some error obtaining the function.
  - getDatabaseProperty
```
String getDatabaseProperty(String name)
                           throws StoredProcedureException
```
    Obtains a database property.
    Parameters:
    name - the name of the property. The available properties are:
    
    CURRENT_USER: The user executing the stored procedure.
    CURRENT_DATABASE: The database where the stored procedure is being executed.
    Returns:
    the value of the property
    
    Throws:
    
    StoredProcedureException - if there is some error retrieving the property
  - log
```
void log(int level,
       String logMessage)
```
    Adds an entry log, with the specified level.
    Parameters:
    level - the desired log level. Should be one of these:
    
    StoredProcedureExecutor#LOG_TRACE
    StoredProcedureExecutor#LOG_DEBUG
    StoredProcedureExecutor#LOG_INFO
    StoredProcedureExecutor#LOG_WARN
    StoredProcedureExecutor#LOG_ERROR
    StoredProcedureExecutor#LOG_FATAL
    logMessage - the message to be logged.
  - executeUpdate
```
int executeUpdate(String query)
                  throws StoredProcedureException
```
    Executes an INSERT, UPDATE or DELETE query.
    
    Parameters:
    query - the query to be executed.
    
    Returns:
    the number of rows affected by the query.
    
    Throws:
    
    StoredProcedureException
  - executeUpdate
```
int executeUpdate(String query,
                Object[] parameterValues)
                  throws StoredProcedureException
```
    Executes a parameterized INSERT, UPDATE or DELETE query.
    
    Parameters:
    query - a VQL query that may contain one or more '?' parameter placeholders
    parameterValues - the list of values to be replaced in the query. The number of elements in this array has to match the number of "?" in the query.
    
    Returns:
    a JDBC ResultSet.
    
    Throws:
    
    StoredProcedureException - if there is some error executing the query, or the parameters supplied are invalid.
  - executeUpdate
```
int executeUpdate(String query,
                Object[] parameterValues,
                long queryTimeout)
                  throws StoredProcedureException
```
    Executes a parameterized INSERT, UPDATE or DELETE query specifying the timeouts.
    
    Parameters:
    query - a VQL query that may contain one or more '?' parameter placeholders
    parameterValues - the list of values to be replaced in the query. The number of elements in this array has to match the number of "?" in the query.
    queryTimeout - query timeout configuration.
    chunkTimeout - chunk timeout configuration.
    chunkSize - chunk size configuration.
    
    Returns:
    a JDBC ResultSet.
    
    Throws:
    
    StoredProcedureException - if there is some error executing the query, or the parameters supplied are invalid.
  - executeVqlCommand
```
String executeVqlCommand(String databaseName,
                       String command)
                         throws StoredProcedureException
```
    Executes a VQL command over the given database. Important: We advise against invoking this method to create/modify/delete elements if this stored procedure is going to run on a production environment.
    
    Parameters:
    databaseName - database where the command is executed
    command - command to be executed
    
    Returns:
    command result
    
    Throws:
    
    StoredProcedureException - if there is some error executing the command, or the parameters supplied are invalid.
  - executeVqlCommand
```
String executeVqlCommand(String command,
                       long queryTimeout)
                         throws StoredProcedureException
```
    Executes a VQL command with a timeout. Important: We advise against invoking this method to create/modify/delete elements if this stored procedure is going to run on a production environment.
    
    Parameters:
    command - command to be executed
    queryTimeout - query timeout configuration.
    
    Returns:
    command result
    
    Throws:
    
    StoredProcedureException - if there is some error executing the command, or the parameters supplied are invalid.
  - executeVqlCommand
```
String executeVqlCommand(String databaseName,
                       String command,
                       long queryTimeout)
                         throws StoredProcedureException
```
    Executes a VQL command over the given database with a timeout. Important: We advise against invoking this method to create/modify/delete elements if this stored procedure is going to run on a production environment.
    
    Parameters:
    databaseName - database where the command is executed
    command - command to be executed
    queryTimeout - query timeout configuration.
    
    Returns:
    command result
    
    Throws:
    
    StoredProcedureException - if there is some error executing the command, or the parameters supplied are invalid.
  - executeVqlCommand
```
String executeVqlCommand(String command)
                         throws StoredProcedureException
```
    Executes a VQL command. Important: We advise against invoking this method to create/modify/delete elements if this stored procedure is going to run on a production environment.
    
    Parameters:
    command - command to be executed
    
    Returns:
    command result
    
    Throws:
    
    StoredProcedureException - if there is some error executing the command, or the parameters supplied are invalid.
  - createTransaction
```
Transaction createTransaction()
                              throws NotSupportedException,
                                     SystemException
```
    Creates a new transaction.
    
    Returns:
    an user transaction
    
    Throws:
    
    NotSupportedException
    
    SystemException
  - joinTransaction
```
void joinTransaction(StoredProcedure storedProcedure)
                     throws RollbackException,
                            SystemException
```
    Joins a stored procedure to the current transaction.
    
    Parameters:
    storedProcedure - the procedure to be joined to the transaction.
    
    Throws:
    
    RollbackException
    
    SystemException

Interface DatabaseEnvironment

Method Summary

Method Detail

executeQuery

executeQuery

executeQuery

executeQuery

lookupProcedure

lookupFunction

getDatabaseProperty

log

executeUpdate

executeUpdate

executeUpdate

executeVqlCommand

executeVqlCommand

executeVqlCommand

executeVqlCommand

createTransaction

joinTransaction