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 JdbcAdapter.supportsFkConstraints() will return 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

protected String

storageEngine

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

ejbqlTranslatorFactory, extendedTypes, identifiersEndQuote, identifiersStartQuote, pkGenerator, supportsBatchUpdates, supportsFkConstraints, supportsGeneratedKeys, supportsUniqueConstraints, typesHandler

Constructor Summary

MySQLAdapter()

Method Summary

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.
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.
String	dropTable(DbEntity table) Deprecated. since 3.0
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()
void	initIdentifiersQuotes()
MergerFactory	mergerFactory()
void	setStorageEngine(String engine)

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

bindParameter, createFkConstraint, createUniqueConstraint, externalTypesForJdbcType, findAdapterResource, findResource, getBatchTerminator, getEjbqlTranslatorFactory, getExtendedTypes, getIdentifiersEndQuote, getIdentifiersStartQuote, getPkGenerator, getQuotingStrategy, setEjbqlTranslatorFactory, setPkGenerator, setSupportsBatchUpdates, setSupportsFkConstraints, setSupportsGeneratedKeys, setSupportsUniqueConstraints, supportsBatchUpdates, supportsFkConstraints, supportsGeneratedKeys, supportsUniqueConstraints, tableTypeForTable, tableTypeForView

Methods inherited from class java.lang.Object

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

Field Detail

storageEngine

protected String storageEngine

Constructor Detail

MySQLAdapter

public MySQLAdapter()

Method Detail

initIdentifiersQuotes

public void initIdentifiersQuotes()

Overrides:

initIdentifiersQuotes in class JdbcAdapter

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

dropTable

public String dropTable(DbEntity table)

Deprecated. since 3.0

Description copied from class: JdbcAdapter

Returns a SQL string to drop a table corresponding to table DbEntity.

Specified by:

dropTable in interface DbAdapter

Overrides:

dropTable in class JdbcAdapter

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

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

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