net.java.ao.db

Class MySQLDatabaseProvider

java.lang.Object

net.java.ao.DatabaseProvider

net.java.ao.db.MySQLDatabaseProvider

All Implemented Interfaces:

Disposable

public class MySQLDatabaseProvider
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

Modifier and Type	Field and Description
static String	TRUNCATE_TO_255_CHARACTERS_FUNCTION

Fields inherited from class net.java.ao.DatabaseProvider

logger, quoteRef, sqlLogger, typeManager

Constructor Summary

Constructors

Constructor and Description
MySQLDatabaseProvider(DisposableDataSource dataSource)

Method Summary

Modifier and Type	Method and Description
protected Set<String>	getReservedWords() Retrieves the set of all reserved words for the underlying database.
boolean	isCaseSensitive() Flag indicating whether or not the underlying database uses case-sensitive identifiers.
void	putNull(PreparedStatement stmt, int index) Stores an SQL NULL value in the database.
protected Iterable<SQLAction>	renderAlterTableAddColumn(NameConverters nameConverters, DDLTable table, DDLField field) Generates the database-specific DDL statements required to add a column to an existing table.
protected Iterable<SQLAction>	renderAlterTableChangeColumn(NameConverters nameConverters, 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	renderAppend() Generates any database-specific options which must be appended to the end of a table definition.
protected String	renderAutoIncrement() Generates the DDL fragment required to specify an INTEGER field as auto-incremented.
protected String	renderConstraintsForTable(UniqueNameConverter uniqueNameConverter, DDLTable table) Renders the foreign key constraints in database-specific DDL for the table in question.
SQLAction	renderCreateCompositeIndex(String tableName, String indexName, List<String> fields) Generates the database-specific DDL statement required to create a new composite index.
protected SQLAction	renderCreateIndex(IndexNameConverter indexNameConverter, DDLIndex index) Generates the database-specific DDL statement required to create a new index.
protected String	renderQueryLimit(Query query) Renders the LIMIT portion of the query in the database-specific SQL dialect.
protected String	renderUnique(UniqueNameConverter uniqueNameConverter, DDLTable table, DDLField field) Renders the UNIQUE constraint as defined by the database-specific DDL syntax.

Methods inherited from class net.java.ao.DatabaseProvider

_getFunctionNameForField, _getTriggerNameForField, _renderDropFunctionForField, _renderDropSequenceForField, _renderDropTriggerForField, _renderFunctionForField, _renderSequenceForField, _renderTriggerForField, addSqlListener, commitTransaction, convertTypeToString, dispose, executeInsertReturningKey, executeUpdate, executeUpdateForAction, executeUpdatesForActions, findForeignKeysForField, getConnection, getDateFormat, getImportedKeys, getIndexes, getMaxIDLength, getSchema, getSequences, getTables, getTypeManager, handleBlob, handleUpdateError, hasIndex, hasIndex, insertReturningKey, isNumericType, isSchemaNotEmpty, loadQuoteString, onSql, parseValue, preparedStatement, preparedStatement, preparedStatement, processID, processOnClause, processOrderClause, processTableName, processWhereClause, putBoolean, querySelectFields, queryTableName, quote, quoteTableName, removeSqlListener, renderAccessories, renderAccessoriesForField, renderAction, renderAlterTableAddColumnStatement, renderAlterTableAddKey, renderAlterTableChangeColumnStatement, renderAlterTableDropColumn, renderAlterTableDropColumnStatement, renderAlterTableDropKey, renderDate, renderDropAccessories, renderDropAccessoriesForField, renderDropColumnActions, renderDropIndex, renderDropTableStatement, renderField, renderFieldDefault, renderFieldOptionsInAlterColumn, renderFields, renderFieldType, renderForeignKey, renderInsert, renderMetadataQuery, renderPrimaryKey, renderQuery, renderQueryGroupBy, renderQueryHaving, renderQueryJoins, renderQueryOrderBy, renderQuerySelect, renderQueryWhere, renderTable, renderValue, rollbackTransaction, setPostConnectionProperties, setQueryResultSetProperties, setQueryStatementProperties, shorten, shouldQuoteID, shouldQuoteTableName, startTransaction, withSchema

Methods inherited from class java.lang.Object

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

Field Detail

TRUNCATE_TO_255_CHARACTERS_FUNCTION

public static final String TRUNCATE_TO_255_CHARACTERS_FUNCTION

See Also:

Constant Field Values

Constructor Detail

MySQLDatabaseProvider

public MySQLDatabaseProvider(DisposableDataSource dataSource)

Method Detail

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

renderAppend

protected String renderAppend()

Description copied from class: DatabaseProvider

Generates any database-specific options which must be appended to the end of a table definition. The only database I am aware of which requires this is MySQL. For example:

CREATE TABLE test (
     id INTEGER NOT NULL AUTO_INCREMENT,
     name VARCHAR(45),
     PRIMARY KEY(id)
 ) ENGINE=InnoDB;

The "ENGINE=InnoDB" clause is what is returned by this method. The default implementation simply returns null, signifying that no append should be rendered.

Overrides:

renderAppend in class DatabaseProvider

Returns:

A DDL clause to be appended to the CREATE TABLE DDL, or null

renderUnique

protected String renderUnique(UniqueNameConverter uniqueNameConverter,
                              DDLTable table,
                              DDLField field)

Description copied from class: DatabaseProvider

Renders the UNIQUE constraint as defined by the database-specific DDL syntax. This method is a delegate of other, more complex methods such as DatabaseProvider.renderField(net.java.ao.schema.NameConverters, net.java.ao.schema.ddl.DDLTable, net.java.ao.schema.ddl.DDLField, net.java.ao.DatabaseProvider.RenderFieldOptions). The default implementation just returns UNIQUE. Implementations may override this method to return an empty String if the database in question does not support the constraint.

Overrides:

renderUnique in class DatabaseProvider

Returns:

The database-specific rendering of UNIQUE.

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.

Unfortunately, we live in the real world of proprietary database implementations that requires us to use database specific keywords or semantics to achieve these outcomes. Appropriate methods should be overridden in such cases.

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.

renderConstraintsForTable

protected String renderConstraintsForTable(UniqueNameConverter uniqueNameConverter,
                                           DDLTable table)

Description copied from class: DatabaseProvider

Renders the foreign key constraints in database-specific DDL for the table in question. Actually, this method only loops through the foreign keys and renders indentation and line-breaks. The actual rendering is done in a second delegate method.

Overrides:

renderConstraintsForTable in class DatabaseProvider

table - The database-agnostic DDL representation of the table in question.

Returns:

The String rendering of all of the foreign keys for the table.

See Also:

DatabaseProvider.renderForeignKey(DDLForeignKey)

renderAlterTableAddColumn

protected Iterable<SQLAction> renderAlterTableAddColumn(NameConverters nameConverters,
                                                        DDLTable table,
                                                        DDLField field)

Description copied from class: DatabaseProvider

Generates the database-specific DDL statements required to add a column to an existing table. Included in the return value should be the statements required to add all necessary functions and triggers to ensure that the column acts appropriately. For example, if the field is tagged with an @OnUpdate annotation, chances are there will be a trigger and possibly a function along with the ALTER statement. These "extra" functions are properly ordered and will only be appended if their values are not null. Because of this, very few database providers will need to override this method.

Each SQLAction should have a corresponding undo action; these will be executed in reverse order if the action needs to be rolled back.

Overrides:

renderAlterTableAddColumn in class DatabaseProvider

table - The table which should receive the new column.

field - The column to add to the specified table.

Returns:

An array of DDL statements to execute.

See Also:

#renderFunctionForField(net.java.ao.schema.TriggerNameConverter, net.java.ao.schema.ddl.DDLTable, net.java.ao.schema.ddl.DDLField), #renderTriggerForField(net.java.ao.schema.TriggerNameConverter, net.java.ao.schema.SequenceNameConverter, net.java.ao.schema.ddl.DDLTable, net.java.ao.schema.ddl.DDLField)

renderAlterTableChangeColumn

protected Iterable<SQLAction> renderAlterTableChangeColumn(NameConverters nameConverters,
                                                           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 DatabaseProvider.renderAlterTableChangeColumnStatement(net.java.ao.schema.NameConverters, net.java.ao.schema.ddl.DDLTable, net.java.ao.schema.ddl.DDLField, net.java.ao.schema.ddl.DDLField, net.java.ao.DatabaseProvider.RenderFieldOptions) method.

Overrides:

renderAlterTableChangeColumn in class DatabaseProvider

table - The table containing the column to change.

oldField - The old column definition.

field - The new column definition (defining the resultant DDL). @return An array of DDL statements to be executed.

See Also:

#getTriggerNameForField(net.java.ao.schema.TriggerNameConverter, net.java.ao.schema.ddl.DDLTable, net.java.ao.schema.ddl.DDLField), #getFunctionNameForField(net.java.ao.schema.TriggerNameConverter, net.java.ao.schema.ddl.DDLTable, net.java.ao.schema.ddl.DDLField), #renderFunctionForField(net.java.ao.schema.TriggerNameConverter, net.java.ao.schema.ddl.DDLTable, net.java.ao.schema.ddl.DDLField), #renderTriggerForField(net.java.ao.schema.TriggerNameConverter, net.java.ao.schema.SequenceNameConverter, net.java.ao.schema.ddl.DDLTable, net.java.ao.schema.ddl.DDLField)

renderCreateIndex

protected SQLAction renderCreateIndex(IndexNameConverter indexNameConverter,
                                      DDLIndex index)

Description copied from class: DatabaseProvider

Generates the database-specific DDL statement required to create a new 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:

renderCreateIndex in class DatabaseProvider

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

Returns:

A DDL statement to be executed.

renderCreateCompositeIndex

public SQLAction renderCreateCompositeIndex(String tableName,
                                            String indexName,
                                            List<String> fields)

Description copied from class: DatabaseProvider

Generates the database-specific DDL statement required to create a new composite index. This is only used by AO integration tests to create a composite index for testing. AO does not provide clients with a feature to manage composite indexes in any way.

Overrides:

renderCreateCompositeIndex in class DatabaseProvider

Parameters:

tableName - The name of the database table

indexName - The name of the new index

fields - List of fields that make up the index

Returns:

A DDL statement to be executed.

putNull

public void putNull(PreparedStatement stmt,
                    int index)
             throws SQLException

Description copied from class: DatabaseProvider

Stores an SQL NULL value in the database. This method is required due to the fact that not all JDBC drivers handle NULLs in the same fashion. The default implementation calls PreparedStatement.setNull(int, int), retrieving parameter type from metadata. Databases which require a different implementation (e.g. PostgreSQL) should override this method.

Overrides:

putNull in class DatabaseProvider

Parameters:

stmt - The statement in which to store the NULL value.

index - The index of the parameter which should be assigned NULL.

Throws:

SQLException

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.

isCaseSensitive

public boolean isCaseSensitive()

Description copied from class: DatabaseProvider

Flag indicating whether or not the underlying database uses case-sensitive 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:

isCaseSensitive in class DatabaseProvider

Returns:

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