org.h2.command.query

类 SelectUnion

java.lang.Object

org.h2.command.Prepared

org.h2.command.query.Query

org.h2.command.query.SelectUnion

public class SelectUnion
extends Query

Represents a union SELECT statement.

嵌套类概要

嵌套类

限定符和类型	类和说明
static class	SelectUnion.UnionType

字段概要

从类继承的字段 org.h2.command.Prepared

create, parameters, prepareAlways, session, sqlStatement, sqlTokens

构造器概要

构造器

构造器和说明
SelectUnion(SessionLocal session, SelectUnion.UnionType unionType, Query query, Query right)

方法概要

限定符和类型	方法和说明
void	addGlobalCondition(Parameter param, int columnId, int comparisonType) Add a condition to the query.
boolean	allowGlobalConditions() Check whether adding condition to the query is allowed.
void	fireBeforeSelectTriggers() Call the before triggers on all tables.
double	getCost() Calculate the cost to execute this query.
LocalResult	getEmptyResult()
Query	getLeft()
String	getPlanSQL(int sqlFlags) Get the SQL statement with the execution plan.
Query	getRight()
HashSet<Table>	getTables() Get all tables that are involved in this query.
SelectUnion.UnionType	getUnionType()
void	init() Initialize the query.
boolean	isConstantQuery() Check if this query will always return the same value and has no side effects.
boolean	isEverything(ExpressionVisitor visitor) Check if this expression and all sub-expressions can fulfill a criteria.
boolean	isUnion() Check if this is a UNION query.
void	mapColumns(ColumnResolver resolver, int level) Map the columns to the given column resolver.
void	prepareExpressions()
void	preparePlan()
protected ResultInterface	queryWithoutCache(long maxRows, ResultTarget target) Execute the query without checking the cache.
void	setEvaluatable(TableFilter tableFilter, boolean b) Change the evaluatable flag.
void	setForUpdate(boolean forUpdate) Set the 'for update' flag.
void	updateAggregate(SessionLocal s, int stage) Update all aggregate function values.

从类继承的方法 org.h2.command.query.Query

collectDependencies, disableCache, exists, getColumnCount, getCostAsExpression, getExpressions, getFetch, getIfSingleRow, getMaxDataModificationId, getOffset, getRowDataType, getType, hasOrder, isAnyDistinct, isFetchPercent, isNeverLazy, isQuery, isRandomAccessResult, isReadOnly, isStandardDistinct, isTransactional, isWithTies, prepare, query, query, queryMeta, setDistinctIfPossible, setFetch, setFetchPercent, setNeverLazy, setOffset, setOrder, setRandomAccessResult, setWithTies, toTable

从类继承的方法 org.h2.command.Prepared

checkCanceled, checkParameters, getCteCleanups, getCurrentRowNumber, getObjectId, getParameters, getPersistedObjectId, getSession, getSimpleSQL, getSQL, getSQLTokens, isCacheable, isWithParamValues, needRecompile, setCommand, setCteCleanups, setCurrentRowNumber, setParameterList, setPersistedObjectId, setPrepareAlways, setRow, setSession, setSQL, setWithParamValues, toString, update

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

构造器详细资料

SelectUnion

public SelectUnion(SessionLocal session,
                   SelectUnion.UnionType unionType,
                   Query query,
                   Query right)

方法详细资料

isUnion

public boolean isUnion()

从类复制的说明: Query

Check if this is a UNION query.

指定者:

isUnion 在类中 Query

返回:

true if this is a UNION query

getUnionType

public SelectUnion.UnionType getUnionType()

getLeft

public Query getLeft()

getRight

public Query getRight()

getEmptyResult

public LocalResult getEmptyResult()

queryWithoutCache

protected ResultInterface queryWithoutCache(long maxRows,
                                            ResultTarget target)

从类复制的说明: Query

Execute the query without checking the cache. If a target is specified, the results are written to it, and the method returns null. If no target is specified, a new LocalResult is created and returned.

指定者:

queryWithoutCache 在类中 Query

参数:

maxRows - the limit as specified in the JDBC method call

target - the target to write results to

返回:

the result

init

public void init()

从类复制的说明: Query

Initialize the query.

指定者:

init 在类中 Query

prepareExpressions

public void prepareExpressions()

指定者:

prepareExpressions 在类中 Query

preparePlan

public void preparePlan()

指定者:

preparePlan 在类中 Query

getCost

public double getCost()

从类复制的说明: Query

Calculate the cost to execute this query.

指定者:

getCost 在类中 Query

返回:

the cost

getTables

public HashSet<Table> getTables()

从类复制的说明: Query

Get all tables that are involved in this query.

指定者:

getTables 在类中 Query

返回:

the set of tables

setForUpdate

public void setForUpdate(boolean forUpdate)

从类复制的说明: Query

Set the 'for update' flag.

指定者:

setForUpdate 在类中 Query

参数:

forUpdate - the new setting

mapColumns

public void mapColumns(ColumnResolver resolver,
                       int level)

从类复制的说明: Query

Map the columns to the given column resolver.

指定者:

mapColumns 在类中 Query

参数:

resolver - the resolver

level - the subquery level (0 is the top level query, 1 is the first subquery level)

setEvaluatable

public void setEvaluatable(TableFilter tableFilter,
                           boolean b)

从类复制的说明: Query

Change the evaluatable flag. This is used when building the execution plan.

指定者:

setEvaluatable 在类中 Query

参数:

tableFilter - the table filter

b - the new value

addGlobalCondition

public void addGlobalCondition(Parameter param,
                               int columnId,
                               int comparisonType)

从类复制的说明: Query

Add a condition to the query. This is used for views.

指定者:

addGlobalCondition 在类中 Query

参数:

param - the parameter

columnId - the column index (0 meaning the first column)

comparisonType - the comparison type

getPlanSQL

public String getPlanSQL(int sqlFlags)

从类复制的说明: Prepared

Get the SQL statement with the execution plan.

覆盖:

getPlanSQL 在类中 Prepared

参数:

sqlFlags - formatting flags

返回:

the execution plan

isEverything

public boolean isEverything(ExpressionVisitor visitor)

从类复制的说明: Query

Check if this expression and all sub-expressions can fulfill a criteria. If any part returns false, the result is false.

指定者:

isEverything 在类中 Query

参数:

visitor - the visitor

返回:

if the criteria can be fulfilled

updateAggregate

public void updateAggregate(SessionLocal s,
                            int stage)

从类复制的说明: Query

Update all aggregate function values.

指定者:

updateAggregate 在类中 Query

参数:

s - the session

stage - select stage

fireBeforeSelectTriggers

public void fireBeforeSelectTriggers()

从类复制的说明: Query

Call the before triggers on all tables.

指定者:

fireBeforeSelectTriggers 在类中 Query

allowGlobalConditions

public boolean allowGlobalConditions()

从类复制的说明: Query

Check whether adding condition to the query is allowed. This is not allowed for views that have an order by and a limit, as it would affect the returned results.

指定者:

allowGlobalConditions 在类中 Query

返回:

true if adding global conditions is allowed

isConstantQuery

public boolean isConstantQuery()

从类复制的说明: Query

Check if this query will always return the same value and has no side effects.

覆盖:

isConstantQuery 在类中 Query

返回:

if this query will always return the same value and has no side effects.