net.java.ao.db
Class EmbeddedDerbyDatabaseProvider

java.lang.Object
  net.java.ao.DatabaseProvider
      net.java.ao.db.EmbeddedDerbyDatabaseProvider

public class EmbeddedDerbyDatabaseProvider
extends DatabaseProvider

Author:

Daniel Spiewak

Nested Class Summary

Nested classes/interfaces inherited from class net.java.ao.DatabaseProvider

DatabaseProvider.RenderFieldOptions, DatabaseProvider.SqlListener

Field Summary

Fields inherited from class net.java.ao.DatabaseProvider

logger, schema, sqlLogger

Constructor Summary

EmbeddedDerbyDatabaseProvider(DisposableDataSource dataSource, String uri)

Method Summary

protected boolean	considerPrecision(DDLField field) Determines whether or not the database allows explicit precisions for the field in question.
protected String	convertTypeToString(DatabaseType<?> type) Converts the specified type into the database-specific DDL String value.
void	dispose() Frees any resources held by the database provider or delegate libraries (such as connection pools).
protected Set<String>	getReservedWords() Retrieves the set of all reserved words for the underlying database.
ResultSet	getTables(Connection conn) Returns a result set of all of the tables (and associated meta) in the database.
protected String	getTriggerNameForField(DDLTable table, DDLField field) Retrieves the name of the trigger which corresponds to the field in question (if any).
Object	handleBlob(ResultSet res, Class<?> type, String field)
boolean	isCaseSensetive() Flag indicating whether or not the underlying database uses case-sensetive identifiers.
Object	parseValue(int type, String value) Parses the database-agnostic String value relevant to the specified SQL type in int form (as defined by Types and returns the Java value which corresponds.
protected List<String>	renderAlterTableChangeColumn(DDLTable table, DDLField oldField, DDLField field) Generates the database-specific DDL statements required to change the given column from its old specification to the given DDL value.
protected String[]	renderAlterTableDropColumn(DDLTable table, DDLField field) Generates the database-specific DDL statements required to remove the specified column from the given table.
protected String	renderAutoIncrement() Generates the DDL fragment required to specify an INTEGER field as auto-incremented.
protected String	renderDropIndex(DDLIndex index) Generates the database-specific DDL statement required to drop an index.
protected String	renderOnUpdate(DDLField field) Renders the appropriate field suffix to allow for the OnUpdate functionality.
protected String	renderQueryLimit(Query query) Renders the LIMIT portion of the query in the database-specific SQL dialect.
protected String	renderTriggerForField(DDLTable table, DDLField field) Renders the trigger which corresponds to the specified field, or null if none.
protected void	setPostConnectionProperties(Connection conn) Called to make any post-creation modifications to a new Connection instance.
void	setQueryResultSetProperties(ResultSet res, Query query) Allows the provider to set database-specific options on a ResultSet instance prior to its use by the library.
void	setQueryStatementProperties(Statement stmt, Query query) Allows the provider to set database-specific options on a Statement instance prior to its usage in a SELECT query.

Methods inherited from class net.java.ao.DatabaseProvider

addSqlListener, commitTransaction, executeInsertReturningKey, executeUpdate, getConnection, getDateFormat, getFunctionNameForField, getMaxIDLength, getSchema, getSequences, handleUpdateError, insertReturningKey, isNumericType, onSql, preparedStatement, preparedStatement, preparedStatement, processID, processOnClause, processWhereClause, putBoolean, putNull, quote, removeSqlListener, renderAction, renderAlterTableAddColumn, renderAlterTableAddKey, renderAlterTableChangeColumnStatement, renderAlterTableDropKey, renderAppend, renderCalendar, renderConstraintsForTable, renderCreateIndex, renderDropFunctions, renderDropSequences, renderDropTable, renderDropTriggers, renderField, renderFieldDefault, renderFieldOptionsInAlterColumn, renderFieldPrecision, renderFieldType, renderForeignKey, renderFunction, renderFunctionForField, renderFunctions, renderInsert, renderQuery, renderQueryGroupBy, renderQueryJoins, renderQueryOrderBy, renderQuerySelect, renderQueryWhere, renderSequences, renderTable, renderTriggers, renderUnique, renderValue, rollbackTransaction, shorten, shouldQuoteID, startTransaction, withSchema

Methods inherited from class java.lang.Object

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

Constructor Detail

EmbeddedDerbyDatabaseProvider

public EmbeddedDerbyDatabaseProvider(DisposableDataSource dataSource,
                                     String uri)

Method Detail

dispose

public void dispose()

Description copied from class: DatabaseProvider

Frees any resources held by the database provider or delegate libraries (such as connection pools). This method should be once usage of the provider is complete to ensure that all connections are committed and closed.

Overrides:

dispose in class DatabaseProvider

setQueryStatementProperties

public void setQueryStatementProperties(Statement stmt,
                                        Query query)
                                 throws SQLException

Description copied from class: DatabaseProvider

Allows the provider to set database-specific options on a Statement instance prior to its usage in a SELECT query. This is to allow things like emulation of the LIMIT feature on databases which don't support it within the SQL implementation.

This method is only called on SELECTs.

Overrides:

setQueryStatementProperties in class DatabaseProvider

Parameters:

stmt - The instance against which the properties should be set.

query - The query which is being executed against the statement instance.

Throws:

SQLException

setQueryResultSetProperties

public void setQueryResultSetProperties(ResultSet res,
                                        Query query)
                                 throws SQLException

Description copied from class: DatabaseProvider

Allows the provider to set database-specific options on a ResultSet instance prior to its use by the library. This allows for features such as row offsetting even on databases that don't support it (such as Oracle, Derby, etc).

Overrides:

setQueryResultSetProperties in class DatabaseProvider

Parameters:

res - The ResultSet to modify.

query - The query instance which was run to produce the result set.

Throws:

SQLException

getTables

public ResultSet getTables(Connection conn)
                    throws SQLException

Description copied from class: DatabaseProvider

Returns a result set of all of the tables (and associated meta) in the database. The fields of the result set must correspond with those specified in the DatabaseMetaData#getTables(String, String, String, String[]) method. In fact, the default implementation merely calls this method passing (null, null, "", null). For databases (such as PostgreSQL) where this is unsuitable, different parameters can be specified to the getTables method in the override, or an entirely new implementation written, as long as the result set corresponds in fields to the JDBC spec.

Overrides:

getTables in class DatabaseProvider

Parameters:

conn - The connection to use in retrieving the database tables.

Returns:

A result set of tables (and meta) corresponding in fields to the JDBC specification.

Throws:

SQLException

See Also:

DatabaseMetaData.getTables(String, String, String, String[])

parseValue

public Object parseValue(int type,
                         String value)

Description copied from class: DatabaseProvider

Parses the database-agnostic String value relevant to the specified SQL type in int form (as defined by Types and returns the Java value which corresponds. This method is completely database-agnostic, as are all of all of its delegate methods.

WARNING: This method is being considered for removal to another class (perhaps TypeManager?) as it is not a database-specific function and thus confuses the purpose of this class. Do not rely upon it heavily. (better yet, don't rely on it at all from external code. It's not designed to be part of the public API)

Overrides:

parseValue in class DatabaseProvider

Parameters:

type - The JDBC integer type of the database field against which to parse the value.

value - The database-agnostic String value to parse into a proper Java object with respect to the specified SQL type.

Returns:

A Java value which corresponds to the specified String.

setPostConnectionProperties

protected void setPostConnectionProperties(Connection conn)
                                    throws SQLException

Description copied from class: DatabaseProvider

Called to make any post-creation modifications to a new Connection instance. This is used for databases such as Derby which require the schema to be set after the connection is created.

Overrides:

setPostConnectionProperties in class DatabaseProvider

Parameters:

conn - The connection to modify according to the database requirements.

Throws:

SQLException

renderQueryLimit

protected String renderQueryLimit(Query query)

Description copied from class: DatabaseProvider

Renders the LIMIT portion of the query in the database-specific SQL dialect. There is wide variety in database implementations of this particular SQL clause. In fact, many database do not support it at all. If the database in question does not support LIMIT, this method should be overridden to return an empty String. For such databases, LIMIT should be implemented by overriding DatabaseProvider.setQueryResultSetProperties(ResultSet, Query) and DatabaseProvider.setQueryStatementProperties(Statement, Query).

An example return value: " LIMIT 10,2"

There is usually no need to call this method directly. Under normal operations it functions as a delegate for DatabaseProvider.renderQuery(Query, TableNameConverter, boolean).

Overrides:

renderQueryLimit in class DatabaseProvider

Parameters:

query - The Query instance from which to determine the LIMIT properties.

Returns:

The database-specific SQL rendering of the LIMIT portion of the query.

convertTypeToString

protected String convertTypeToString(DatabaseType<?> type)

Description copied from class: DatabaseProvider

Converts the specified type into the database-specific DDL String value. By default, this delegates to the DatabaseType#getDefaultName() method. Subclass implementations should be sure to make a super call in order to ensure that both default naming and future special cases are handled appropriately.

Overrides:

convertTypeToString in class DatabaseProvider

Parameters:

type - The type instance to convert to a DDL string.

Returns:

The database-specific DDL representation of the type (e.g. "VARCHAR").

See Also:

DatabaseType.getDefaultName()

renderAutoIncrement

protected String renderAutoIncrement()

Description copied from class: DatabaseProvider

Generates the DDL fragment required to specify an INTEGER field as auto-incremented. For databases which do not support such flags (which is just about every database exception MySQL), "" is an acceptable return value. This method should never return null as it would cause the field rendering method to throw a NullPointerException.

Overrides:

renderAutoIncrement in class DatabaseProvider

renderOnUpdate

protected String renderOnUpdate(DDLField field)

Description copied from class: DatabaseProvider

Renders the appropriate field suffix to allow for the OnUpdate functionality. For most databases (read: all but MySQL) this will return an empty String. This is because few databases provide an implicit ON UPDATE syntax for fields. As such, most databases will be compelled to return an empty String and implement the functionality using triggers.

Overrides:

renderOnUpdate in class DatabaseProvider

Parameters:

field - The field for which the ON UPDATE clause should be rendered.

Returns:

The database-specific ON UPDATE field clause.

handleBlob

public Object handleBlob(ResultSet res,
                         Class<?> type,
                         String field)
                  throws SQLException

Overrides:

handleBlob in class DatabaseProvider

Throws:

SQLException

renderTriggerForField

protected String renderTriggerForField(DDLTable table,
                                       DDLField field)

Description copied from class: DatabaseProvider

Renders the trigger which corresponds to the specified field, or null if none. This is to allow for databases which require the use of triggers to provide functionality such as ON UPDATE. The default implementation returns null.

Overrides:

renderTriggerForField in class DatabaseProvider

Parameters:

table - The table containing the field for which a trigger may need to be rendered.

field - The field for which the trigger should be rendered, if any.

Returns:

A database-specific DDL statement creating a trigger for the field in question, or null.

See Also:

DatabaseProvider.getTriggerNameForField(DDLTable, DDLField)

getTriggerNameForField

protected String getTriggerNameForField(DDLTable table,
                                        DDLField field)

Description copied from class: DatabaseProvider

Retrieves the name of the trigger which corresponds to the field in question (if any). If no trigger will be automatically created for the specified field, null should be returned. This function is to allow for databases which require the use of triggers on a field to allow for certain functionality (like ON UPDATE). The default implementation returns null.

Overrides:

getTriggerNameForField in class DatabaseProvider

Parameters:

table - The table which contains the field for which a trigger may or may not exist.

field - The field for which a previous migration may have created a trigger.

Returns:

The unique name of the trigger which was created for the field, or null if none.

See Also:

DatabaseProvider.renderTriggerForField(DDLTable, DDLField)

considerPrecision

protected boolean considerPrecision(DDLField field)

Description copied from class: DatabaseProvider

Determines whether or not the database allows explicit precisions for the field in question. This is to support databases such as Derby which do not support precisions for certain types. By default, this method returns true.

More often than not, all that is required for this determination is the type. As such, the method signature may change in a future release.

Overrides:

considerPrecision in class DatabaseProvider

Parameters:

field - The field for which precision should/shouldn't be rendered.

Returns:

true if precision should be rendered, otherwise false.

renderAlterTableChangeColumn

protected List<String> renderAlterTableChangeColumn(DDLTable table,
                                                    DDLField oldField,
                                                    DDLField field)

Description copied from class: DatabaseProvider

Generates the database-specific DDL statements required to change the given column from its old specification to the given DDL value. This method will also generate the appropriate statements to remove old triggers and functions, as well as add new ones according to the requirements of the new field definition.

The default implementation of this method functions in the manner specified by the MySQL database. Some databases will have to perform more complicated actions (such as dropping and re-adding the field) in order to satesfy the same use-case. Such databases should print a warning to stderr to ensure that the end-developer is aware of such restrictions.

Thus, the specification for this method allows for data loss. Nevertheless, if the database supplies a mechanism to accomplish the task without data loss, it should be applied.

For maximum flexibility, the default implementation of this method only deals with the dropping and addition of functions and triggers. The actual generation of the ALTER TABLE statement is done in the #renderAlterTableChangeColumnStatement(net.java.ao.schema.ddl.DDLTable, net.java.ao.schema.ddl.DDLField, net.java.ao.schema.ddl.DDLField, boolean) method.

Overrides:

renderAlterTableChangeColumn in class DatabaseProvider

Parameters:

table - The table containing the column to change.

oldField - The old column definition.

field - The new column definition (defining the resultant DDL).

Returns:

An array of DDL statements to be executed.

See Also:

DatabaseProvider.getTriggerNameForField(DDLTable, DDLField), DatabaseProvider.getFunctionNameForField(DDLTable, DDLField), DatabaseProvider.renderFunctionForField(DDLTable, DDLField), DatabaseProvider.renderTriggerForField(DDLTable, DDLField)

renderAlterTableDropColumn

protected String[] renderAlterTableDropColumn(DDLTable table,
                                              DDLField field)

Description copied from class: DatabaseProvider

Generates the database-specific DDL statements required to remove the specified column from the given table. This should also generate the necessary statements to drop all triggers and functions associated with the column in question. If the database being implemented has a non-standard syntax for dropping functions and/or triggers, it may be required to override this method, even if the syntax to drop columns is standard.

Overrides:

renderAlterTableDropColumn in class DatabaseProvider

Parameters:

table - The table from which to drop the column.

field - The column definition to remove from the table.

Returns:

An array of DDL statements to be executed.

See Also:

DatabaseProvider.getTriggerNameForField(DDLTable, DDLField), DatabaseProvider.getFunctionNameForField(DDLTable, DDLField)

renderDropIndex

protected String renderDropIndex(DDLIndex index)

Description copied from class: DatabaseProvider

Generates the database-specific DDL statement required to drop an index. The syntax for this operation is highly standardized and thus it is unlikely this method will be overridden. If the database in question does not support indexes, a warning should be printed to stderr and null returned.

Overrides:

renderDropIndex in class DatabaseProvider

Parameters:

index - The index to drop. This single instance contains all of the data necessary to drop the index, thus no separate parameters (such as a DDLTable) are required.

Returns:

A DDL statement to be executed, or null.

getReservedWords

protected Set<String> getReservedWords()

Description copied from class: DatabaseProvider

Retrieves the set of all reserved words for the underlying database. The set returns should be speculative, meaning that it should include any possible reserved words, not just those for a particular version. As an implementation guideline, the Set instance returned from this method should guarentee O(1) lookup times, otherwise ORM performance will suffer greatly.

Specified by:

getReservedWords in class DatabaseProvider

Returns:

A set of upper case reserved words specific to the database.

isCaseSensetive

public boolean isCaseSensetive()

Description copied from class: DatabaseProvider

Flag indicating whether or not the underlying database uses case-sensetive identifiers. This specifically affects comparisons in the SchemaReader utility. The default value is true. Note that databases which support both case-sensetive and case-insensetive identifiers (like MySQL) should return true for better all-around compatibility.

Overrides:

isCaseSensetive in class DatabaseProvider

Returns:

boolean true if identifiers are case-sensetive, false otherwise.