oracle.toplink.essentials.queryframework.ReadQuery Maven / Gradle / Ivy
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package oracle.toplink.essentials.queryframework;
import oracle.toplink.essentials.internal.sessions.AbstractRecord;
import oracle.toplink.essentials.internal.sessions.AbstractSession;
/**
* Purpose:
* Abstract class for all read queries.
*
*
Responsibilities:
*
* - Caches result of query if flag is set.
*
*
* @author Yvon Lavoie
* @since TOPLink/Java 1.0
*/
public abstract class ReadQuery extends DatabaseQuery {
/** Used for retrieve limited rows through the query. */
protected int maxRows;
/** Used to start query results at a specific result */
protected int firstResult;
/* used on read queries to stamp the object to determine the last time it was refreshed to
* reduce work and prevent inifinite recursion on Refreshes
*CR #4365 - used to prevent infinit recursion on refresh object cascade all
* CR #2698903 - fix for the previous fix. No longer using millis but ids now.
*/
protected long queryId;
/**
* PUBLIC:
* Initialize the state of the query
*/
public ReadQuery() {
this.maxRows = 0;
this.firstResult = 0;
this.queryId = 0;
}
/**
* INTERNAL:
* By default return the row.
* Used by cursored stream.
*/
public Object buildObject(AbstractRecord row) {
return row;
}
/**
* INTERNAL
* Used to give the subclasses oportunity to copy aspects of the cloned query
* to the original query.
*/
protected void clonedQueryExecutionComplete(DatabaseQuery query, AbstractSession session) {
// Nothing by default.
}
/**
* PUBLIC:
* Return the value that will be set for the firstResult in the returned result set
*/
public int getFirstResult() {
return firstResult;
}
/**
* INTERNAL:
* This method is used to get the time in millis that this query is being executed at.
* it is set just prior to executing the SQL and will be used to determine which objects should be refreshed.
* CR #4365
* CR #2698903 ... instead of using millis we will now use id's instead. Method
* renamed appropriately.
*/
public long getQueryId() {
return this.queryId;
}
/**
* PUBLIC:
* Return the limit for the maximum number of rows that any ResultSet can contain to the given number.
*/
public int getMaxRows() {
return this.maxRows;
}
/**
* PUBLIC:
* Return if this is a read query.
*/
public boolean isReadQuery() {
return true;
}
/**
* PUBLIC:
* Used to set the first result in any result set that is returned for this query.
* This method should only be set once per query. To change the firstReslt use another query.
* This method will call the absolute method on the JDBC result set to move the initial row
* used by TopLink. Note: The set of results returned from the database will still include
* the results before the first result. TopLink will just not use them for object building.
*/
public void setFirstResult(int firstResult) {
this.firstResult = firstResult;
setIsPrepared(false);
shouldCloneCall=true;
}
/**
* INTERNAL:
* This method is used to set the current system time in millis that this query is being executed at.
* it is set just prior to executing the SQL and will be used to determine which objects should be refreshed.
* CR #4365
* CR #2698903 ... instead of using millis we will now use id's instead. Method
* renamed appropriately.
*/
public void setQueryId(long id) {
this.queryId = id;
}
/**
* PUBLIC:
* Used to set the limit for the maximum number of rows that any ResultSet can contain to the given number.
* This method should only be set once per query. To change the max rows use another query.
* This method limits the number of candidate results returned to TopLink that can be used to build objects
*/
public void setMaxRows(int maxRows) {
this.maxRows = maxRows;
setIsPrepared(false);
shouldCloneCall=true;
}
}