org.datanucleus.store.rdbms.query
Class SQLQuery

java.lang.Object
  org.datanucleus.store.query.Query
      org.datanucleus.store.query.AbstractSQLQuery
          org.datanucleus.store.rdbms.query.SQLQuery

All Implemented Interfaces:

Serializable

public final class SQLQuery
extends org.datanucleus.store.query.AbstractSQLQuery

A Query using SQL, and keeping to the JDO2 definition of a SQL query. The majority of this has to be specified in the query filter itself. There are no variables/imports. Ordering/grouping is explicit in the query.

Results

Results from this type of query will be :-

• resultClass - each row of the ResultSet is converted into an instance of the result class
• candidateClass - each row of the ResultSet is converted into an instance of the candidate
• Object[] - when no candidate or result class specified
• Long - when the query is an INSERT/UPDATE/DELETE/MERGE

Parameters

Parameters to this type of query can be :-

• Positional : The SQL statement includes "?" and the parameters are positional starting at 1 (just like in JDBC).
• Numbered : The SQL statement includes "?1", "?2" etc (with numbers starting at 1) and the users input of parameters at execute is of the numbered parameters.
• Named : The SQL statement includes ":myParam1", ":myOtherParam" etc and the users input of parameters via "executeWithMap" includes values for all specified names.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.datanucleus.store.query.Query

org.datanucleus.store.query.Query.SubqueryDefinition

Field Summary

protected boolean	isCompiled State variable for the compilation state
protected static org.datanucleus.util.Localiser	LOCALISER_RDBMS Localiser of messages.
protected org.datanucleus.store.mapped.StatementMappingIndex[]	stmtMappings Mappings for the result of the query.

Fields inherited from class org.datanucleus.store.query.AbstractSQLQuery

compiledSQL, inputSQL, resultMetaData

Fields inherited from class org.datanucleus.store.query.Query

BULK_DELETE, BULK_UPDATE, candidateClass, candidateClassName, clr, compilation, ec, explicitParameters, explicitVariables, EXTENSION_CHECK_UNUSED_PARAMETERS, EXTENSION_COMPILATION_CACHED, EXTENSION_EVALUATE_IN_MEMORY, EXTENSION_FLUSH_BEFORE_EXECUTION, EXTENSION_LOAD_RESULTS_AT_COMMIT, EXTENSION_MULTITHREAD, EXTENSION_RESULT_CACHE_TYPE, EXTENSION_RESULT_SIZE_METHOD, EXTENSION_RESULTS_CACHED, EXTENSION_USE_FETCH_PLAN, extensions, filter, from, fromInclNo, fromInclParam, grouping, having, ignoreCache, implicitParameters, imports, inputParameters, LOCALISER, ordering, OTHER, parameterNames, parsedImports, queryResults, range, result, resultClass, resultClassName, resultDistinct, SELECT, storeMgr, subclasses, subqueries, tasks, toExclNo, toExclParam, type, unique, unmodifiable, update

Constructor Summary

SQLQuery(org.datanucleus.store.StoreManager storeMgr, org.datanucleus.store.ExecutionContext ec)
Constructs a new query instance having the same criteria as the given query.

SQLQuery(org.datanucleus.store.StoreManager storeMgr, org.datanucleus.store.ExecutionContext ec, SQLQuery query)
Constructor for a new query using the existing query.

SQLQuery(org.datanucleus.store.StoreManager storeMgr, org.datanucleus.store.ExecutionContext ec, String queryString)
Constructs a new query instance for the provided single-string SQL query.

Method Summary

protected void	assertSupportsCancel() Method that will throw an UnsupportedOperationException if the query implementation doesn't support cancelling queries.
static boolean	columnNamesAreTheSame(org.datanucleus.store.mapped.DatastoreAdapter dba, String name1, String name2) Convenience method to compare two column names.
void	compileInternal(Map parameterValues) Verify the elements of the query and provide a hint to the query to prepare and optimize an execution plan.
protected void	discardCompiled() Utility to remove any previous compilation of this Query.
boolean	equals(Object obj) Equality operator.
protected String	generateQueryStatement() Method to perform any necessary pre-processing on the users query statement before we execute it.
protected org.datanucleus.store.query.ResultObjectFactory	getResultObjectFactoryForCandidateClass(ResultSet rs) Method to generate a ResultObjectFactory for converting rows of the provided ResultSet into instances of the candidate class.
protected boolean	isCompiled() Method to return if the query is compiled.
protected Object	performExecute(Map parameters) Execute the query and return the result.
boolean	processesRangeInDatastoreQuery()

Methods inherited from class org.datanucleus.store.query.AbstractSQLQuery

declareExplicitParameters, declareExplicitVariables, declareImports, executeWithArray, executeWithMap, getInputSQL, getLanguage, performDeletePersistentAll, prepareForExecution, setCandidates, setCandidates, setFilter, setGrouping, setOrdering, setRange, setResult, setResultClass, setResultMetaData, setSubclasses, shouldReturnSingleRow

Methods inherited from class org.datanucleus.store.query.Query

addExtension, addSubquery, applyImplicitParameterValueToCompilation, applyImplicitParameterValueToSubqueries, assertIsModifiable, cancel, cancel, cancelTaskObject, checkForMissingParameters, checkParameterTypesAgainstCompilation, checkUnusedParameters, close, closeAll, compile, deepFindSymbolForParameterInCompilation, deletePersistentAll, deletePersistentAll, deletePersistentAll, deregisterTask, execute, executeQuery, getBooleanExtensionProperty, getCandidateClass, getCandidateClassName, getCompilation, getDatastoreReadTimeoutMillis, getDatastoreWriteTimeoutMillis, getExecutionContext, getExplicitParameters, getExplicitVariables, getExtension, getExtensions, getFetchPlan, getFilter, getFrom, getGrouping, getHaving, getIgnoreCache, getImplicitParameters, getImports, getInputParameters, getOrdering, getParameterMapForValues, getParsedImports, getQueryManager, getRange, getRangeFromIncl, getRangeFromInclParam, getRangeToExcl, getRangeToExclParam, getResult, getResultClass, getResultClassName, getResultDistinct, getSerializeRead, getStoreManager, getStringExtensionProperty, getSubqueryForVariable, getSupportedExtensions, getType, getUpdate, hashCode, hasSubqueryForVariable, isSubclasses, isUnique, isUnmodifiable, prepareDatastore, registerTask, resolveClassDeclaration, setCacheResults, setCandidateClass, setCandidateClassName, setCompilation, setDatastoreReadTimeoutMillis, setDatastoreWriteTimeoutMillis, setExtensions, setFetchPlan, setFrom, setHaving, setIgnoreCache, setImplicitParameter, setImplicitParameter, setRange, setRange, setResultClassName, setResultDistinct, setSerializeRead, setType, setUnique, setUnmodifiable, setUpdate, supportsTimeout, useCaching, useFetchPlan, useResultsCaching

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Field Detail

LOCALISER_RDBMS

protected static final org.datanucleus.util.Localiser LOCALISER_RDBMS

Localiser of messages.

isCompiled

protected transient boolean isCompiled

State variable for the compilation state

stmtMappings

protected transient org.datanucleus.store.mapped.StatementMappingIndex[] stmtMappings

Mappings for the result of the query.

Constructor Detail

SQLQuery

public SQLQuery(org.datanucleus.store.StoreManager storeMgr,
                org.datanucleus.store.ExecutionContext ec,
                SQLQuery query)

Constructor for a new query using the existing query.

Parameters:

storeMgr - StoreManager for this query

ec - execution context

query - The existing query

SQLQuery

public SQLQuery(org.datanucleus.store.StoreManager storeMgr,
                org.datanucleus.store.ExecutionContext ec)

Constructs a new query instance having the same criteria as the given query.

Parameters:

storeMgr - StoreManager for this query

ec - execution context

SQLQuery

public SQLQuery(org.datanucleus.store.StoreManager storeMgr,
                org.datanucleus.store.ExecutionContext ec,
                String queryString)

Constructs a new query instance for the provided single-string SQL query.

Parameters:

storeMgr - StoreManager for this query

ec - execution context

queryString - The SQL query string

Method Detail

equals

public boolean equals(Object obj)

Equality operator.

Overrides:

equals in class org.datanucleus.store.query.Query

Parameters:

obj - The object to compare against

Returns:

Whether they are equal

discardCompiled

protected void discardCompiled()

Utility to remove any previous compilation of this Query.

Overrides:

discardCompiled in class org.datanucleus.store.query.AbstractSQLQuery

isCompiled

protected boolean isCompiled()

Method to return if the query is compiled.

Overrides:

isCompiled in class org.datanucleus.store.query.Query

Returns:

Whether it is compiled

processesRangeInDatastoreQuery

public boolean processesRangeInDatastoreQuery()

Overrides:

processesRangeInDatastoreQuery in class org.datanucleus.store.query.Query

compileInternal

public void compileInternal(Map parameterValues)

Verify the elements of the query and provide a hint to the query to prepare and optimize an execution plan.

Specified by:

compileInternal in class org.datanucleus.store.query.Query

performExecute

protected Object performExecute(Map parameters)

Execute the query and return the result. For a SELECT query this will be the QueryResult. For an UPDATE/DELETE it will be the row count for the update statement.

Specified by:

performExecute in class org.datanucleus.store.query.Query

Parameters:

parameters - the Map containing all of the parameters (positional parameters) (not null)

Returns:

the result of the query

assertSupportsCancel

protected void assertSupportsCancel()

Method that will throw an UnsupportedOperationException if the query implementation doesn't support cancelling queries.

Overrides:

assertSupportsCancel in class org.datanucleus.store.query.Query

getResultObjectFactoryForCandidateClass

protected org.datanucleus.store.query.ResultObjectFactory getResultObjectFactoryForCandidateClass(ResultSet rs)
                                                                                           throws SQLException

Method to generate a ResultObjectFactory for converting rows of the provided ResultSet into instances of the candidate class. Populates stmtMappings.

Parameters:

rs - The ResultSet

Returns:

The ResultObjectFactory

Throws:

SQLException - Thrown if an error occurs processing the ResultSet

columnNamesAreTheSame

public static boolean columnNamesAreTheSame(org.datanucleus.store.mapped.DatastoreAdapter dba,
                                            String name1,
                                            String name2)

Convenience method to compare two column names. Allows for case sensitivity issues, and for database added quoting.

Parameters:

dba - Datastore adapter

name1 - The first name (from the datastore)

name2 - The second name (from the user SQL statement)

Returns:

Whether they are the same

generateQueryStatement

protected String generateQueryStatement()

Method to perform any necessary pre-processing on the users query statement before we execute it. SQL queries are not modified in any way, as per JDO2 spec [14.7].

Returns:

The compiled SQL statement