org.h2.engine.Comment Maven / Gradle / Ivy
/*
* Copyright 2004-2019 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (https://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.engine;
import org.h2.message.DbException;
import org.h2.message.Trace;
import org.h2.table.Table;
import org.h2.util.StringUtils;
/**
* Represents a database object comment.
*/
public class Comment extends DbObjectBase {
private final int objectType;
private final String quotedObjectName;
private String commentText;
public Comment(Database database, int id, DbObject obj) {
super(database, id, getKey(obj), Trace.DATABASE);
this.objectType = obj.getType();
this.quotedObjectName = obj.getSQL(true);
}
@Override
public String getCreateSQLForCopy(Table table, String quotedName) {
throw DbException.throwInternalError(toString());
}
private static String getTypeName(int type) {
switch (type) {
case DbObject.CONSTANT:
return "CONSTANT";
case DbObject.CONSTRAINT:
return "CONSTRAINT";
case DbObject.FUNCTION_ALIAS:
return "ALIAS";
case DbObject.INDEX:
return "INDEX";
case DbObject.ROLE:
return "ROLE";
case DbObject.SCHEMA:
return "SCHEMA";
case DbObject.SEQUENCE:
return "SEQUENCE";
case DbObject.TABLE_OR_VIEW:
return "TABLE";
case DbObject.TRIGGER:
return "TRIGGER";
case DbObject.USER:
return "USER";
case DbObject.DOMAIN:
return "DOMAIN";
default:
// not supported by parser, but required when trying to find a
// comment
return "type" + type;
}
}
@Override
public String getDropSQL() {
return null;
}
@Override
public String getCreateSQL() {
StringBuilder buff = new StringBuilder("COMMENT ON ");
buff.append(getTypeName(objectType)).append(' ').
append(quotedObjectName).append(" IS ");
if (commentText == null) {
buff.append("NULL");
} else {
StringUtils.quoteStringSQL(buff, commentText);
}
return buff.toString();
}
@Override
public int getType() {
return DbObject.COMMENT;
}
@Override
public void removeChildrenAndResources(Session session) {
database.removeMeta(session, getId());
}
@Override
public void checkRename() {
DbException.throwInternalError();
}
/**
* Get the comment key name for the given database object. This key name is
* used internally to associate the comment to the object.
*
* @param obj the object
* @return the key name
*/
static String getKey(DbObject obj) {
StringBuilder builder = new StringBuilder(getTypeName(obj.getType())).append(' ');
obj.getSQL(builder, true);
return builder.toString();
}
/**
* Set the comment text.
*
* @param comment the text
*/
public void setCommentText(String comment) {
this.commentText = comment;
}
}