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* to you under the Apache License, Version 2.0 (the
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package org.apache.cayenne.dba.mysql;
import java.sql.Types;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import org.apache.cayenne.CayenneRuntimeException;
import org.apache.cayenne.access.DataNode;
import org.apache.cayenne.access.jdbc.EJBQLTranslatorFactory;
import org.apache.cayenne.access.trans.QualifierTranslator;
import org.apache.cayenne.access.trans.QueryAssembler;
import org.apache.cayenne.access.types.ByteArrayType;
import org.apache.cayenne.access.types.CharType;
import org.apache.cayenne.access.types.ExtendedTypeMap;
import org.apache.cayenne.dba.JdbcAdapter;
import org.apache.cayenne.dba.PkGenerator;
import org.apache.cayenne.dba.QuotingStrategy;
import org.apache.cayenne.dba.TypesMapping;
import org.apache.cayenne.map.DbAttribute;
import org.apache.cayenne.map.DbEntity;
import org.apache.cayenne.map.DbRelationship;
import org.apache.cayenne.map.Relationship;
import org.apache.cayenne.merge.MergerFactory;
import org.apache.cayenne.query.Query;
import org.apache.cayenne.query.SQLAction;
/**
* DbAdapter implementation for <a href="http://www.mysql.com">MySQL RDBMS</a>. <h3>
* Foreign Key Constraint Handling</h3>
* <p>
* Foreign key constraints are supported by InnoDB engine and NOT supported by MyISAM
* engine. This adapter by default assumes MyISAM, so
* {@link org.apache.cayenne.dba.JdbcAdapter#supportsFkConstraints()} will return false.
* Users can manually change this by calling <em>setSupportsFkConstraints(true)</em> or
* better by using an {@link org.apache.cayenne.dba.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 <em>table_type</em> MySQL variable to detect whether InnoDB
* is the default, and configure the adapter accordingly.
* <h3>Sample Connection Settings</h3>
* <ul>
* <li>Adapter name: org.apache.cayenne.dba.mysql.MySQLAdapter</li>
* <li>DB URL: jdbc:mysql://serverhostname/dbname</li>
* <li>Driver Class: com.mysql.jdbc.Driver</li>
* </ul>
*/
public class MySQLAdapter extends JdbcAdapter {
final static String DEFAULT_STORAGE_ENGINE = "InnoDB";
final static String MYSQL_QUOTE_SQL_IDENTIFIERS_CHAR_START = "`";
final static String MYSQL_QUOTE_SQL_IDENTIFIERS_CHAR_END = "`";
protected String storageEngine;
protected boolean supportsFkConstraints;
public MySQLAdapter() {
// init defaults
this.storageEngine = DEFAULT_STORAGE_ENGINE;
setSupportsBatchUpdates(true);
setSupportsFkConstraints(true);
setSupportsUniqueConstraints(true);
setSupportsGeneratedKeys(true);
initIdentifiersQuotes();
}
void setSupportsFkConstraints(boolean flag) {
this.supportsFkConstraints = flag;
}
@Override
public void initIdentifiersQuotes() {
this.identifiersStartQuote = MYSQL_QUOTE_SQL_IDENTIFIERS_CHAR_START;
this.identifiersEndQuote = MYSQL_QUOTE_SQL_IDENTIFIERS_CHAR_END;
}
@Override
public QualifierTranslator getQualifierTranslator(QueryAssembler queryAssembler) {
return new MySQLQualifierTranslator(queryAssembler);
}
/**
* Uses special action builder to create the right action.
*
* @since 1.2
*/
@Override
public SQLAction getAction(Query query, DataNode node) {
return query.createSQLAction(new MySQLActionBuilder(this, node
.getEntityResolver()));
}
/**
* @since 3.0
*/
@Override
public Collection<String> dropTableStatements(DbEntity table) {
// note that CASCADE is a noop as of MySQL 5.0, so we have to use FK checks
// statement
StringBuffer buf = new StringBuffer();
QuotingStrategy context = getQuotingStrategy(table
.getDataMap()
.isQuotingSQLIdentifiers());
buf.append(context.quoteFullyQualifiedName(table));
return Arrays.asList("SET FOREIGN_KEY_CHECKS=0", "DROP TABLE IF EXISTS "
+ buf.toString()
+ " CASCADE", "SET FOREIGN_KEY_CHECKS=1");
}
/**
* Installs appropriate ExtendedTypes used as converters for passing values between
* JDBC and Java layers.
*/
@Override
protected void configureExtendedTypes(ExtendedTypeMap map) {
super.configureExtendedTypes(map);
// must handle CLOBs as strings, otherwise there
// are problems with NULL clobs that are treated
// as empty strings... somehow this doesn't happen
// for BLOBs (ConnectorJ v. 3.0.9)
map.registerType(new CharType(false, false));
map.registerType(new ByteArrayType(false, false));
}
@Override
public DbAttribute buildAttribute(
String name,
String typeName,
int type,
int size,
int precision,
boolean allowNulls) {
if (typeName != null) {
typeName = typeName.toLowerCase();
}
// all LOB types are returned by the driver as OTHER... must remap them manually
// (at least on MySQL 3.23)
if (type == Types.OTHER) {
if ("longblob".equals(typeName)) {
type = Types.BLOB;
}
else if ("mediumblob".equals(typeName)) {
type = Types.BLOB;
}
else if ("blob".equals(typeName)) {
type = Types.BLOB;
}
else if ("tinyblob".equals(typeName)) {
type = Types.VARBINARY;
}
else if ("longtext".equals(typeName)) {
type = Types.CLOB;
}
else if ("mediumtext".equals(typeName)) {
type = Types.CLOB;
}
else if ("text".equals(typeName)) {
type = Types.CLOB;
}
else if ("tinytext".equals(typeName)) {
type = Types.VARCHAR;
}
}
// types like "int unsigned" map to Long
else if (typeName != null && typeName.endsWith(" unsigned")) {
// per
// http://dev.mysql.com/doc/refman/5.0/en/connector-j-reference-type-conversions.html
if (typeName.equals("int unsigned")
|| typeName.equals("integer unsigned")
|| typeName.equals("mediumint unsigned")) {
type = Types.BIGINT;
}
// BIGINT UNSIGNED maps to BigInteger according to MySQL docs, but there is no
// JDBC mapping for BigInteger
}
return super.buildAttribute(name, typeName, type, size, precision, allowNulls);
}
/**
* Creates and returns a primary key generator. Overrides superclass implementation to
* return an instance of MySQLPkGenerator that does the correct table locking.
*/
@Override
protected PkGenerator createPkGenerator() {
return new MySQLPkGenerator(this);
}
/**
* @since 3.0
*/
@Override
protected EJBQLTranslatorFactory createEJBQLTranslatorFactory() {
return new MySQLEJBQLTranslatorFactory();
}
/**
* Overrides super implementation to explicitly set table engine to InnoDB if FK
* constraints are supported by this adapter.
*/
@Override
public String createTable(DbEntity entity) {
String ddlSQL = super.createTable(entity);
if (storageEngine != null) {
ddlSQL += " ENGINE=" + storageEngine;
}
return ddlSQL;
}
/**
* 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.
*
* @since 1.2
*/
// See CAY-358 for details of the InnoDB problem
@Override
protected void createTableAppendPKClause(StringBuffer sqlBuffer, DbEntity entity) {
boolean status;
if (entity.getDataMap() != null && entity.getDataMap().isQuotingSQLIdentifiers()) {
status = true;
}
else {
status = false;
}
QuotingStrategy context = getQuotingStrategy(status);
// must move generated to the front...
List<DbAttribute> pkList = new ArrayList<DbAttribute>(entity.getPrimaryKeys());
Collections.sort(pkList, new PKComparator());
Iterator<DbAttribute> pkit = pkList.iterator();
if (pkit.hasNext()) {
sqlBuffer.append(", PRIMARY KEY (");
boolean firstPk = true;
while (pkit.hasNext()) {
if (firstPk)
firstPk = false;
else
sqlBuffer.append(", ");
DbAttribute at = pkit.next();
sqlBuffer.append(context.quoteString(at.getName()));
}
sqlBuffer.append(')');
}
// if FK constraints are supported, we must add indices to all FKs
// Note that according to MySQL docs, FK indexes are created automatically when
// constraint is defined, starting at MySQL 4.1.2
if (supportsFkConstraints) {
for (Relationship r : entity.getRelationships()) {
DbRelationship relationship = (DbRelationship) r;
if (relationship.getJoins().size() > 0
&& relationship.isToPK()
&& !relationship.isToDependentPK()) {
sqlBuffer.append(", KEY (");
Iterator<DbAttribute> columns = relationship
.getSourceAttributes()
.iterator();
DbAttribute column = columns.next();
sqlBuffer.append(context.quoteString(column.getName()));
while (columns.hasNext()) {
column = columns.next();
sqlBuffer.append(", ").append(
context.quoteString(column.getName()));
}
sqlBuffer.append(")");
}
}
}
}
/**
* Appends AUTO_INCREMENT clause to the column definition for generated columns.
*/
@Override
public void createTableAppendColumn(StringBuffer sqlBuffer, DbAttribute column) {
boolean status;
if ((column.getEntity().getDataMap() != null)
&& column.getEntity().getDataMap().isQuotingSQLIdentifiers()) {
status = true;
}
else {
status = false;
}
QuotingStrategy context = getQuotingStrategy(status);
String[] types = externalTypesForJdbcType(column.getType());
if (types == null || types.length == 0) {
String entityName = column.getEntity() != null ? ((DbEntity) column
.getEntity()).getFullyQualifiedName() : "<null>";
throw new CayenneRuntimeException("Undefined type for attribute '"
+ entityName
+ "."
+ column.getName()
+ "': "
+ column.getType());
}
String type = types[0];
sqlBuffer.append(context.quoteString(column.getName()));
sqlBuffer.append(' ').append(type);
// append size and precision (if applicable)s
if (TypesMapping.supportsLength(column.getType())) {
int len = column.getMaxLength();
int scale = TypesMapping.isDecimal(column.getType()) ? column.getScale() : -1;
// sanity check
if (scale > len) {
scale = -1;
}
if (len > 0) {
sqlBuffer.append('(').append(len);
if (scale >= 0) {
sqlBuffer.append(", ").append(scale);
}
sqlBuffer.append(')');
}
}
sqlBuffer.append(column.isMandatory() ? " NOT NULL" : " NULL");
if (column.isGenerated()) {
sqlBuffer.append(" AUTO_INCREMENT");
}
}
@Override
public MergerFactory mergerFactory() {
return new MySQLMergerFactory();
}
final class PKComparator implements Comparator<DbAttribute> {
public int compare(DbAttribute a1, DbAttribute a2) {
if (a1.isGenerated() != a2.isGenerated()) {
return a1.isGenerated() ? -1 : 1;
}
else {
return a1.getName().compareTo(a2.getName());
}
}
}
/**
* @since 3.0
*/
public String getStorageEngine() {
return storageEngine;
}
/**
* @since 3.0
*/
public void setStorageEngine(String engine) {
this.storageEngine = engine;
}
}