/*
* RHQ Management Platform
* Copyright (C) 2005-2008 Red Hat, Inc.
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
package org.rhq.core.db.ant.dbupgrade;
import java.sql.Connection;
import java.sql.SQLException;
import mazz.i18n.Msg;
import org.apache.tools.ant.BuildException;
import org.rhq.core.db.DatabaseType;
import org.rhq.core.db.ant.DbAntI18NFactory;
import org.rhq.core.db.ant.DbAntI18NResourceKeys;
/**
* Ant task that can alter an existing column. This task requires these attributes:
*
* <ul>
* <li>table</li>
* <li>column</li>
* <li>columnType + (the new column's generic type)</li>
* <li>nullable + (if <code>true</code>, the column can be NULL; otherwise it is NOT NULL)</li>
* <li>default + (the new default value of the column)</li>
* </ul>
*
* + where only one of columnType, nullable or default is required. This task has two optional attributes:
*
* <ul>
* <li>precision</li>
* <li>reindex - if <code>true</code>, the table will be re-indexed</li>
* </ul>
*/
public class SST_AlterColumn extends SchemaSpecTask {
private static final Msg MSG = DbAntI18NFactory.getMsg();
private String table = null;
private String column = null;
private String columnType = null;
private String precision = null;
private String defval = null;
private Boolean nullable = null;
private Boolean reindex = null;
/**
* Sets the table name whose column is to be altered.
*
* @param t table name
*/
public void setTable(String t) {
table = t;
}
/**
* Sets the name of the column that is to be altered.
*
* @param c column name
*/
public void setColumn(String c) {
column = c;
}
/**
* Sets the column's new generic column type.
*
* @param ct generic column type
*/
public void setColumnType(String ct) {
columnType = ct;
}
/**
* Sets the column's new precision.
*
* @param p precision
*/
public void setPrecision(String p) {
precision = p;
}
/**
* Sets the new nullable setting for the column - if true it can be null, if false it cannot. The value of this
* attribute can be either true/false or respectively "NULL"/"NOT NULL".
*
* @param n nullable boolean string
*
* @throws IllegalArgumentException if boolean string is neither true nor false
*/
public void setNullable(String n) {
if (n.equalsIgnoreCase("true") || n.equalsIgnoreCase("NULL")) {
nullable = Boolean.TRUE;
} else if (n.equalsIgnoreCase("false") || n.equalsIgnoreCase("NOT NULL")) {
nullable = Boolean.FALSE;
} else {
throw new IllegalArgumentException("nullable=" + n);
}
}
/**
* Sets the new default value of the column.
*
* @param d default value
*/
public void setDefault(String d) {
defval = d;
}
/**
* Sets the reindex flag - this is a boolean string, "true" or "false".
*
* @param r reindex flag
*
* @throws IllegalArgumentException if boolean string is neither true nor false
*/
public void setReindex(String r) {
if (r.equalsIgnoreCase("true")) {
reindex = Boolean.TRUE;
} else if (r.equalsIgnoreCase("false")) {
reindex = Boolean.FALSE;
} else {
throw new IllegalArgumentException("reindex=" + r);
}
}
/**
* @see org.apache.tools.ant.Task#execute()
*/
public void execute() throws BuildException {
validateAttributes();
if (!isDBTargeted()) {
return;
}
try {
DatabaseType db_type = getDatabaseType();
Connection conn = getConnection();
checkColumnExistence(conn, db_type);
db_type.alterColumn(conn, table, column, columnType, defval, precision, nullable, reindex);
} catch (Exception e) {
throw new BuildException(MSG.getMsg(DbAntI18NResourceKeys.ALTER_COLUMN_ERROR, e), e);
}
}
/**
* Checks to see if the column exists. If it does not, we can't alter the column so an exception is thrown.
*
* @param conn
* @param db_type
*
* @throws SQLException failed to determine if the column exists or not
* @throws BuildException column does not exist
*/
private void checkColumnExistence(Connection conn, DatabaseType db_type) throws BuildException, SQLException {
boolean exists = db_type.checkColumnExists(conn, table, column);
if (!exists) {
throw new BuildException(MSG.getMsg(DbAntI18NResourceKeys.ALTER_COLUMN_DOES_NOT_EXIST, table, column));
}
}
private void validateAttributes() throws BuildException {
if (table == null) {
throw new BuildException(MSG.getMsg(DbAntI18NResourceKeys.SCHEMA_SPEC_TASK_MISSING_ATTRIB, "AlterColumn",
"table"));
}
if (column == null) {
throw new BuildException(MSG.getMsg(DbAntI18NResourceKeys.SCHEMA_SPEC_TASK_MISSING_ATTRIB, "AlterColumn",
"column"));
}
if ((columnType == null) && (nullable == null) && (defval == null)) {
throw new BuildException(MSG.getMsg(DbAntI18NResourceKeys.SCHEMA_SPEC_TASK_MISSING_ATTRIB, "AlterColumn",
"columnType|default|nullable"));
}
}
}