org.apache.cayenne.dba.mysql

Class MySQLAdapter

java.lang.Object

org.apache.cayenne.dba.JdbcAdapter

org.apache.cayenne.dba.mysql.MySQLAdapter

All Implemented Interfaces:

DbAdapter

public class MySQLAdapter
extends JdbcAdapter

DbAdapter implementation for MySQL RDBMS.

Foreign Key Constraint Handling

Foreign key constraints are supported by InnoDB engine and NOT supported by MyISAM engine. This adapter by default assumes MyISAM, so supportsFkConstraints will be false. Users can manually change this by calling setSupportsFkConstraints(true) or better by using an AutoAdapter, i.e. not entering the adapter name at all for the DataNode, letting Cayenne guess it in runtime. In the later case Cayenne will check the table_type MySQL variable to detect whether InnoDB is the default, and configure the adapter accordingly.

Sample Connection Settings

• Adapter name: org.apache.cayenne.dba.mysql.MySQLAdapter
• DB URL: jdbc:mysql://serverhostname/dbname
• Driver Class: com.mysql.jdbc.Driver

Field Summary

Fields

Modifier and Type	Field and Description
protected String	storageEngine
protected boolean	supportsFkConstraints

Fields inherited from class org.apache.cayenne.dba.JdbcAdapter

batchQueryBuilderFactory, caseInsensitiveCollations, ejbqlTranslatorFactory, extendedTypes, logger, quotingStrategy, resourceLocator, supportsBatchUpdates, supportsGeneratedKeys, supportsUniqueConstraints, typesHandler

Constructor Summary

Constructors

Constructor and Description
MySQLAdapter(RuntimeProperties runtimeProperties, List<ExtendedType> defaultExtendedTypes, List<ExtendedType> userExtendedTypes, List<ExtendedTypeFactory> extendedTypeFactories, ResourceLocator resourceLocator)

Method Summary

Methods

Modifier and Type	Method and Description
void	bindParameter(PreparedStatement statement, Object object, int pos, int sqlType, int scale) Binds an object value to PreparedStatement's numbered parameter.
DbAttribute	buildAttribute(String name, String typeName, int type, int size, int precision, boolean allowNulls) Creates and returns a DbAttribute based on supplied parameters (usually obtained from database meta data).
protected void	configureExtendedTypes(ExtendedTypeMap map) Installs appropriate ExtendedTypes used as converters for passing values between JDBC and Java layers.
protected EJBQLTranslatorFactory	createEJBQLTranslatorFactory() Creates and returns an EJBQLTranslatorFactory used to generate visitors for EJBQL to SQL translations.
protected PkGenerator	createPkGenerator() Creates and returns a primary key generator.
protected QuotingStrategy	createQuotingStrategy()
String	createTable(DbEntity entity) Overrides super implementation to explicitly set table engine to InnoDB if FK constraints are supported by this adapter.
void	createTableAppendColumn(StringBuffer sqlBuffer, DbAttribute column) Appends AUTO_INCREMENT clause to the column definition for generated columns.
protected void	createTableAppendPKClause(StringBuffer sqlBuffer, DbEntity entity) Customizes PK clause semantics to ensure that generated columns are in the beginning of the PK definition, as this seems to be a requirement for InnoDB tables.
Collection<String>	dropTableStatements(DbEntity table) Returns a collection of SQL statements needed to drop a database table.
SQLAction	getAction(Query query, DataNode node) Uses special action builder to create the right action.
QualifierTranslator	getQualifierTranslator(QueryAssembler queryAssembler) Creates and returns a default implementation of a qualifier translator.
String	getStorageEngine()
MergerFactory	mergerFactory()
void	setStorageEngine(String engine)
boolean	typeSupportsLength(int type) Returns true if supplied type can have a length attribute as a part of column definition

Methods inherited from class org.apache.cayenne.dba.JdbcAdapter

createFkConstraint, createUniqueConstraint, externalTypesForJdbcType, findResource, getBatchQueryBuilderFactory, getBatchTerminator, getEjbqlTranslatorFactory, getExtendedTypes, getJdbcEventLogger, getPkGenerator, getQuotingStrategy, getQuotingStrategy, getType, initExtendedTypes, setBatchQueryBuilderFactory, setEjbqlTranslatorFactory, setPkGenerator, setSupportsBatchUpdates, setSupportsGeneratedKeys, setSupportsUniqueConstraints, sizeAndPrecision, supportsBatchUpdates, supportsGeneratedKeys, supportsUniqueConstraints, tableTypeForTable, tableTypeForView, unwrap

Methods inherited from class java.lang.Object

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

Field Detail

storageEngine

protected String storageEngine

supportsFkConstraints

protected boolean supportsFkConstraints

Constructor Detail

MySQLAdapter

public MySQLAdapter(RuntimeProperties runtimeProperties,
            List<ExtendedType> defaultExtendedTypes,
            List<ExtendedType> userExtendedTypes,
            List<ExtendedTypeFactory> extendedTypeFactories,
            ResourceLocator resourceLocator)

Method Detail

createQuotingStrategy

protected QuotingStrategy createQuotingStrategy()

Overrides:

createQuotingStrategy in class JdbcAdapter

Returns:

getQualifierTranslator

public QualifierTranslator getQualifierTranslator(QueryAssembler queryAssembler)

Description copied from class: JdbcAdapter

Creates and returns a default implementation of a qualifier translator.

Specified by:

getQualifierTranslator in interface DbAdapter

Overrides:

getQualifierTranslator in class JdbcAdapter

getAction

public SQLAction getAction(Query query,
                  DataNode node)

Uses special action builder to create the right action.

Specified by:

getAction in interface DbAdapter

Overrides:

getAction in class JdbcAdapter

Since:

1.2

dropTableStatements

public Collection<String> dropTableStatements(DbEntity table)

Description copied from interface: DbAdapter

Returns a collection of SQL statements needed to drop a database table.

Specified by:

dropTableStatements in interface DbAdapter

Overrides:

dropTableStatements in class JdbcAdapter

Since:

3.0

configureExtendedTypes

protected void configureExtendedTypes(ExtendedTypeMap map)

Installs appropriate ExtendedTypes used as converters for passing values between JDBC and Java layers.

Overrides:

configureExtendedTypes in class JdbcAdapter

buildAttribute

public DbAttribute buildAttribute(String name,
                         String typeName,
                         int type,
                         int size,
                         int precision,
                         boolean allowNulls)

Description copied from interface: DbAdapter

Creates and returns a DbAttribute based on supplied parameters (usually obtained from database meta data).

Specified by:

buildAttribute in interface DbAdapter

Overrides:

buildAttribute in class JdbcAdapter

Parameters:

name - database column name

typeName - database specific type name, may be used as a hint to determine the right JDBC type.

type - JDBC column type

size - database column size (ignored if less than zero)

precision - database column scale, i.e. the number of decimal digits (ignored if less than zero)

allowNulls - database column nullable parameter

bindParameter

public void bindParameter(PreparedStatement statement,
                 Object object,
                 int pos,
                 int sqlType,
                 int scale)
                   throws SQLException,
                          Exception

Description copied from interface: DbAdapter

Binds an object value to PreparedStatement's numbered parameter.

Specified by:

bindParameter in interface DbAdapter

Overrides:

bindParameter in class JdbcAdapter

Throws:

SQLException

Exception

createPkGenerator

protected PkGenerator createPkGenerator()

Creates and returns a primary key generator. Overrides superclass implementation to return an instance of MySQLPkGenerator that does the correct table locking.

Overrides:

createPkGenerator in class JdbcAdapter

createEJBQLTranslatorFactory

protected EJBQLTranslatorFactory createEJBQLTranslatorFactory()

Description copied from class: JdbcAdapter

Creates and returns an EJBQLTranslatorFactory used to generate visitors for EJBQL to SQL translations. This method should be overriden by subclasses that need to customize EJBQL generation.

Overrides:

createEJBQLTranslatorFactory in class JdbcAdapter

Since:

3.0

createTable

public String createTable(DbEntity entity)

Overrides super implementation to explicitly set table engine to InnoDB if FK constraints are supported by this adapter.

Specified by:

createTable in interface DbAdapter

Overrides:

createTable in class JdbcAdapter

createTableAppendPKClause

protected void createTableAppendPKClause(StringBuffer sqlBuffer,
                             DbEntity entity)

Customizes PK clause semantics to ensure that generated columns are in the beginning of the PK definition, as this seems to be a requirement for InnoDB tables.

Overrides:

createTableAppendPKClause in class JdbcAdapter

Since:

1.2

createTableAppendColumn

public void createTableAppendColumn(StringBuffer sqlBuffer,
                           DbAttribute column)

Appends AUTO_INCREMENT clause to the column definition for generated columns.

Specified by:

createTableAppendColumn in interface DbAdapter

Overrides:

createTableAppendColumn in class JdbcAdapter

Parameters:

sqlBuffer - the StringBuffer to append the column type to

column - the DbAttribute defining the column to append type for

typeSupportsLength

public boolean typeSupportsLength(int type)

Description copied from class: JdbcAdapter

Returns true if supplied type can have a length attribute as a part of column definition

Specified by:

typeSupportsLength in interface DbAdapter

Overrides:

typeSupportsLength in class JdbcAdapter

mergerFactory

public MergerFactory mergerFactory()

Specified by:

mergerFactory in interface DbAdapter

Overrides:

mergerFactory in class JdbcAdapter

getStorageEngine

public String getStorageEngine()

Since:

3.0

setStorageEngine

public void setStorageEngine(String engine)

Since:

3.0