org.efaps.db.databases.MySQLDatabase Maven / Gradle / Ivy
/*
* Copyright 2003 - 2012 The eFaps Team
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Revision: $Rev: 7483 $
* Last Changed: $Date: 2012-05-11 11:57:38 -0500 (Fri, 11 May 2012) $
* Last Changed By: $Author: [email protected] $
*/
package org.efaps.db.databases;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Map;
import org.efaps.db.databases.information.TableInformation;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Database class for the MySQL database.
*
* @author The eFaps Team
* @version $Id: MySQLDatabase.java 7483 2012-05-11 16:57:38Z [email protected] $
*/
public class MySQLDatabase
extends AbstractDatabase
{
/**
* Logging instance used in this class.
*/
private static final Logger LOG = LoggerFactory.getLogger(PostgreSQLDatabase.class);
/**
* Prefix used for tables which simulates sequences.
*
* @see #createSequence(Connection, String, long)
* @see #deleteSequence(Connection, String)
* @see #existsSequence(Connection, String)
* @see #nextSequence(Connection, String)
* @see #setSequence(Connection, String, long)
*/
private static final String PREFIX_SEQUENCE = "seq_";
/**
* Select statement to select all unique keys for current logged in
* MySQL database user.
*
* @see #initTableInfoUniqueKeys(Connection, String, Map)
*/
private static final String SQL_UNIQUE_KEYS = "select "
+ "a.constraint_name as INDEX_NAME, "
+ "a.table_name as TABLE_NAME, "
+ "b.column_name as COLUMN_NAME, "
+ "b.ordinal_position as ORDINAL_POSITION "
+ "from "
+ "information_schema.table_constraints a,"
+ "information_schema.key_column_usage b "
+ "where "
+ "a.constraint_type='UNIQUE' "
+ "and a.table_schema=b.table_schema "
+ "and a.table_name=b.table_name "
+ "and a.constraint_name=b.constraint_name";
/**
* Select statement for all foreign keys for current logged in MySQL
* database user.
*
* @see #initTableInfoForeignKeys(Connection, String, Map)
*/
private static final String SQL_FOREIGN_KEYS = "select "
+ "a.TABLE_NAME as TABLE_NAME, "
+ "a.CONSTRAINT_NAME as FK_NAME, "
+ "b.COLUMN_NAME as FKCOLUMN_NAME, "
+ "'' as DELETE_RULE, "
+ "b.REFERENCED_TABLE_NAME as PKTABLE_NAME, "
+ "b.REFERENCED_COLUMN_NAME as PKCOLUMN_NAME "
+ "from "
+ "information_schema.table_constraints a, "
+ "information_schema.key_column_usage b "
+ "where "
+ "a.constraint_type='FOREIGN KEY' "
+ "and a.CONSTRAINT_SCHEMA=b.CONSTRAINT_SCHEMA "
+ "and a.CONSTRAINT_NAME=b.CONSTRAINT_NAME ";
/**
* Initializes the mapping between the eFaps column types and the MySQL
* specific column types.
*/
public MySQLDatabase()
{
addMapping(ColumnType.INTEGER, "bigint", "null", "bigint", "integer", "int", "mediumint");
addMapping(ColumnType.DECIMAL, "decimal", "null", "decimal", "dec");
addMapping(ColumnType.REAL, "double", "null", "double", "float");
addMapping(ColumnType.STRING_SHORT, "varchar", "null", "text", "tinytext");
addMapping(ColumnType.STRING_LONG, "varchar", "null", "varchar");
addMapping(ColumnType.DATETIME, "datetime", "null", "datetime", "timestamp");
addMapping(ColumnType.BLOB, "longblob", "null", "longblob", "mediumblob", "blob", "tinyblob",
"varbinary", "binary");
addMapping(ColumnType.CLOB, "longtext", "null", "longtext");
addMapping(ColumnType.BOOLEAN, "boolean", "null", "boolean", "bool", "tinyint", "bit");
}
/**
* {@inheritDoc}
*/
@Override
public boolean isConnected(final Connection _connection)
{
// FIXME must be implemented
return false;
}
/**
* @see org.efaps.db.databases.AbstractDatabase#getCurrentTimeStamp()
* @return "current_timestamp"
*/
@Override
public String getCurrentTimeStamp()
{
return "current_timestamp";
}
/**
* {@inheritDoc}
*/
@Override
public String getTimestampValue(final String _isoDateTime)
{
return "timestamp '" + _isoDateTime + "'";
}
/**
* {@inheritDoc}
*/
@Override
public Object getBooleanValue(final Boolean _value)
{
return _value;
}
/**
* This is the MySQL specific implementation of an all deletion.
* Following order is used to remove all eFaps specific information:
*
* - remove all views of the user
* - remove all tables of the user
* - remove all sequences of the user
*
* The table are dropped with cascade, so all depending sequences etc.
* are also dropped automatically.
* Attention! If application specific tables, views or constraints are
* defined, this database objects are also removed!
*
* @param _con sql connection
* @throws SQLException on error while executing sql statements
*/
@Override
public void deleteAll(final Connection _con)
throws SQLException
{
final Statement stmtSel = _con.createStatement();
final Statement stmtExec = _con.createStatement();
try {
if (MySQLDatabase.LOG.isInfoEnabled()) {
MySQLDatabase.LOG.info("Remove all Tables");
}
final DatabaseMetaData metaData = _con.getMetaData();
// delete all views
final ResultSet rsViews = metaData.getTables(null, null, "%", new String[] { "VIEW" });
while (rsViews.next()) {
final String viewName = rsViews.getString("TABLE_NAME");
if (MySQLDatabase.LOG.isDebugEnabled()) {
MySQLDatabase.LOG.debug(" - View '" + viewName + "'");
}
stmtExec.execute("drop view " + viewName);
}
rsViews.close();
// delete all constraints
final ResultSet rsTables = metaData.getTables(null, null, "%", new String[] { "TABLE" });
while (rsTables.next()) {
final String tableName = rsTables.getString("TABLE_NAME");
final ResultSet rsf = _con.getMetaData().getImportedKeys(null, null, tableName);
while (rsf.next()) {
final String fkName = rsf.getString("FK_NAME").toUpperCase();
if (MySQLDatabase.LOG.isDebugEnabled()) {
MySQLDatabase.LOG.debug(" - Foreign Key '" + fkName + "'");
}
stmtExec.execute("alter table " + tableName + " drop foreign key " + fkName);
}
}
// delete all tables
rsTables.beforeFirst();
while (rsTables.next()) {
final String tableName = rsTables.getString("TABLE_NAME");
if (MySQLDatabase.LOG.isDebugEnabled()) {
MySQLDatabase.LOG.debug(" - Table '" + tableName + "'");
}
stmtExec.execute("drop table " + tableName + " cascade");
}
rsTables.close();
} finally {
stmtSel.close();
stmtExec.close();
}
}
/**
* {@inheritDoc}
*/
@Override
public MySQLDatabase deleteView(final Connection _con,
final String _name)
throws SQLException
{
final Statement stmtExec = _con.createStatement();
stmtExec.execute("drop view " + _name);
return this;
}
/**
* For the MySQL database, an eFaps SQL table is created in this steps.
*
* - SQL table itself with column
ID and unique key on the
* column is created
* - if the table is an auto increment table (parent table is
*
null, the column ID is set as auto increment
* column
* - if no parent table is defined, the foreign key to the parent table is
* automatically set
*
*
* @see org.efaps.db.databases.AbstractDatabase#createTable(java.sql.Connection, java.lang.String, java.lang.String)
* @param _con Connection to be used for the SQL statements
* @param _table name for the table
* @return this MySQL DB definition instance
* @throws SQLException if the table could not be created
*/
@Override
public MySQLDatabase createTable(final Connection _con,
final String _table)
throws SQLException
{
final Statement stmt = _con.createStatement();
try {
stmt.executeUpdate(new StringBuilder()
.append("create table `").append(_table).append("` (")
.append("`ID` bigint ")
.append(",").append("constraint `").append(_table).append("_PK_ID` primary key (`ID`)")
.append(") engine InnoDB character set utf8;")
.toString());
} finally {
stmt.close();
}
return this;
}
/**
* {@inheritDoc}
*/
@Override
public MySQLDatabase defineTableAutoIncrement(final Connection _con,
final String _table)
throws SQLException
{
final Statement stmt = _con.createStatement();
try {
// define for ID column the auto increment value
stmt.execute(new StringBuilder()
.append("alter table `").append(_table)
.append("` modify column `ID` bigint not null auto_increment")
.toString());
} finally {
stmt.close();
}
return this;
}
/**
* Overwrites original method because MySQL supports automatically
* generated keys.
*
* @return always true because generated keys are supported by MySQL
* database
* @see AbstractDatabase#supportsGetGeneratedKeys()
*/
@Override
public boolean supportsGetGeneratedKeys()
{
return true;
}
/**
* Overwrites original method because MySQL supports binary input stream.
*
* @return always true because supported by MySQL database
* @see AbstractDatabase#supportsBinaryInputStream()
*/
@Override
public boolean supportsBinaryInputStream()
{
return true;
}
/**
* Returns a single reversed apostrophe ` used to select tables within
* SQL statements for a MySQL database..
*
* @return always single reversed apostrophe
*/
@Override
public String getTableQuote()
{
return "`";
}
/**
* Returns a single reversed apostrophe ` used to select columns within
* SQL statements for a MySQL database..
*
* @return always single reversed apostrophe
*/
@Override
public String getColumnQuote()
{
return "`";
}
/**
* Creates a table with auto generated keys with table name as
* concatenation of the prefix {@link #PREFIX_SEQUENCE} and the lower case
* of _name. This table "simulates" the sequences (which are
* not supported by MySQL).
*
* @param _con SQL connection
* @param _name name of the sequence
* @param _startValue start value of the sequence number
* @return this instance
* @throws SQLException if SQL table could not be created; defined as auto
* increment table or if the sequence number could not
* be defined
* @see #createTable(Connection, String)
* @see #defineTableAutoIncrement(Connection, String)
* @see #setSequence(Connection, String, long)
* @see #PREFIX_SEQUENCE
*/
@Override
public MySQLDatabase createSequence(final Connection _con,
final String _name,
final long _startValue)
throws SQLException
{
final String name = new StringBuilder()
.append(MySQLDatabase.PREFIX_SEQUENCE).append(_name.toLowerCase())
.toString();
createTable(_con, name);
defineTableAutoIncrement(_con, name);
setSequence(_con, _name, _startValue);
return this;
}
/**
* Deletes given sequence _name which is internally
* represented by this MySQL connector as normal SQL table. The name of the
* SQL table to delete is a concatenation of {@link #PREFIX_SEQUENCE} and
* _name in lower case.
*
* @param _con SQL connection
* @param _name name of the sequence
* @return this instance
* @throws SQLException if sequence (simulated by an auto increment SQL
* table) could not be deleted
* @see #PREFIX_SEQUENCE
*/
@Override
public MySQLDatabase deleteSequence(final Connection _con,
final String _name)
throws SQLException
{
final String cmd = new StringBuilder()
.append("DROP TABLE `").append(MySQLDatabase.PREFIX_SEQUENCE).append(_name.toLowerCase()).append("`")
.toString();
final Statement stmt = _con.createStatement();
try {
stmt.executeUpdate(cmd);
} finally {
stmt.close();
}
return this;
}
/**
* Checks if the related table representing sequence _name
* exists.
*
* @param _con SQL connection
* @param _name name of the sequence
* @return true if a table with name as concatenation of
* {@link #PREFIX_SEQUENCE} and _name (in lower case)
* representing the sequence exists; otherwise false
* @throws SQLException if check for the existence of the table
* representing the sequence failed
* @see #existsTable(Connection, String)
* @see #PREFIX_SEQUENCE
*/
@Override
public boolean existsSequence(final Connection _con,
final String _name)
throws SQLException
{
return existsTable(
_con,
new StringBuilder().append(MySQLDatabase.PREFIX_SEQUENCE).append(_name.toLowerCase()).toString());
}
/**
* Fetches next number for sequence _name by inserting new
* row into representing table. The new auto generated key is returned as
* next number of the sequence.
*
* @param _con SQL connection
* @param _name name of the sequence
* @return current inserted value of the table
* @throws SQLException if next number from the sequence could not be
* fetched
* @see #PREFIX_SEQUENCE
*/
@Override
public long nextSequence(final Connection _con,
final String _name)
throws SQLException
{
final long ret;
final Statement stmt = _con.createStatement();
try {
// insert new line
final String insertCmd = new StringBuilder()
.append("INSERT INTO `").append(MySQLDatabase.PREFIX_SEQUENCE).append(_name.toLowerCase())
.append("` VALUES ()")
.toString();
final int row = stmt.executeUpdate(insertCmd, Statement.RETURN_GENERATED_KEYS);
if (row != 1) {
throw new SQLException("no sequence found for '" + _name + "'");
}
// fetch new number
final ResultSet resultset = stmt.getGeneratedKeys();
if (resultset.next()) {
ret = resultset.getLong(1);
} else {
throw new SQLException("no sequence found for '" + _name + "'");
}
} finally {
stmt.close();
}
return ret;
}
/**
* Defines new _value for sequence _name. Because
* in MySQL the sequences are simulated and the values from fetched
* sequence numbers are not deleted, all existing values in the table are
* first deleted (to be sure that the sequence could be reseted to already
* fetched numbers). After the new starting value is defined a first auto
* generated value is fetched from the database so that this value is also
* stored if the MySQL database is restarted.
*
* @param _con SQL connection
* @param _name name of the sequence
* @param _value new value of the sequence
* @return this instance
* @throws SQLException if new number of the sequence could not be defined
* for the table
* @see #PREFIX_SEQUENCE
*/
@Override
public MySQLDatabase setSequence(final Connection _con,
final String _name,
final long _value)
throws SQLException
{
final String name = _name.toLowerCase();
final String lockCmd = new StringBuilder()
.append("LOCK TABLES `").append(MySQLDatabase.PREFIX_SEQUENCE).append(name)
.append("` WRITE")
.toString();
final String deleteCmd = new StringBuilder()
.append("DELETE FROM `").append(MySQLDatabase.PREFIX_SEQUENCE).append(name).append("`")
.toString();
final String alterCmd = new StringBuilder()
.append("ALTER TABLE `").append(MySQLDatabase.PREFIX_SEQUENCE).append(name)
.append("` AUTO_INCREMENT=").append(_value - 1)
.toString();
final String insertCmd = new StringBuilder()
.append("INSERT INTO `").append(MySQLDatabase.PREFIX_SEQUENCE).append(name)
.append("` VALUES ()")
.toString();
final String unlockCmd = new StringBuilder()
.append("UNLOCK TABLES")
.toString();
final Statement stmt = _con.createStatement();
try {
stmt.executeUpdate(lockCmd);
stmt.executeUpdate(deleteCmd);
stmt.executeUpdate(alterCmd);
stmt.executeUpdate(insertCmd);
stmt.executeUpdate(unlockCmd);
} finally {
stmt.close();
}
return this;
}
/**
* Overwrites the original method to specify SQL statement
* {@link #SQL_UNIQUE_KEYS} as replacement because the JDBC driver for
* MySQL does not handle matching table names.
*
* @param _con SQL connection
* @param _sql SQL statement (not used)
* @param _cache4Name map used to fetch depending on the table name the
* related table information
* @throws SQLException if unique keys could not be fetched
* @see #SQL_UNIQUE_KEYS
*/
@Override
protected void initTableInfoUniqueKeys(final Connection _con,
final String _sql,
final Map _cache4Name)
throws SQLException
{
super.initTableInfoUniqueKeys(_con, MySQLDatabase.SQL_UNIQUE_KEYS, _cache4Name);
}
/**
* Overwrites the original method to specify SQL statement
* {@link #SQL_FOREIGN_KEYS} as replacement because the JDBC driver for
* MySQL does not handle matching table names.
*
* @param _con SQL connection
* @param _sql SQL statement (not used)
* @param _cache4Name map used to fetch depending on the table name the
* related table information
* @throws SQLException if foreign keys could not be fetched
* @see #SQL_FOREIGN_KEYS
*/
@Override
protected void initTableInfoForeignKeys(final Connection _con,
final String _sql,
final Map _cache4Name)
throws SQLException
{
super.initTableInfoForeignKeys(_con, MySQLDatabase.SQL_FOREIGN_KEYS, _cache4Name);
}
}
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