org.h2.expression

类 ConditionInSelect

java.lang.Object

org.h2.expression.Expression

org.h2.expression.ConditionInSelect

public class ConditionInSelect
extends Expression

An 'in' condition with a subquery, as in WHERE ID IN(SELECT ...)

构造器概要

构造器

构造器和说明
ConditionInSelect(Database database, Expression left, Query query, boolean all, int compareType)

方法概要

限定符和类型	方法和说明
void	createIndexConditions(Session session, TableFilter filter) Create index conditions if possible and attach them to the table filter.
int	getCost() Estimate the cost to process the expression.
int	getDisplaySize() Get the display size of this expression.
long	getPrecision() Get the precision of this expression.
int	getScale() Get the scale of this expression.
String	getSQL() Get the SQL statement of this expression.
int	getType() Return the data type.
Value	getValue(Session session) Return the resulting value for the current row.
boolean	isEverything(ExpressionVisitor visitor) Check if this expression and all sub-expressions can fulfill a criteria.
void	mapColumns(ColumnResolver resolver, int level) Map the columns of the resolver to expression columns.
Expression	optimize(Session session) Try to optimize the expression.
void	setEvaluatable(TableFilter tableFilter, boolean b) Tell the expression columns whether the table filter can return values now.
void	updateAggregate(Session session) Update an aggregate value.

从类继承的方法 org.h2.expression.Expression

addFilterConditions, getAlias, getBooleanValue, getColumnName, getExpressionColumns, getExpressionColumns, getNonAliasExpression, getNotIfPossible, getNullable, getSchemaName, getTableAlias, getTableName, isAutoIncrement, isConstant, isValueSet, isWildcard, toString

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

ConditionInSelect

public ConditionInSelect(Database database,
                         Expression left,
                         Query query,
                         boolean all,
                         int compareType)

方法详细资料

getValue

public Value getValue(Session session)

从类复制的说明: Expression

Return the resulting value for the current row.

指定者:

getValue 在类中 Expression

参数:

session - the session

返回:

the result

mapColumns

public void mapColumns(ColumnResolver resolver,
                       int level)

从类复制的说明: Expression

Map the columns of the resolver to expression columns.

指定者:

mapColumns 在类中 Expression

参数:

resolver - the column resolver

level - the subquery nesting level

optimize

public Expression optimize(Session session)

从类复制的说明: Expression

Try to optimize the expression.

指定者:

optimize 在类中 Expression

参数:

session - the session

返回:

the optimized expression

setEvaluatable

public void setEvaluatable(TableFilter tableFilter,
                           boolean b)

从类复制的说明: Expression

Tell the expression columns whether the table filter can return values now. This is used when optimizing the query.

指定者:

setEvaluatable 在类中 Expression

参数:

tableFilter - the table filter

b - true if the table filter can return value

getSQL

public String getSQL()

从类复制的说明: Expression

Get the SQL statement of this expression. This may not always be the original SQL statement, specially after optimization.

指定者:

getSQL 在类中 Expression

返回:

the SQL statement

updateAggregate

public void updateAggregate(Session session)

从类复制的说明: Expression

Update an aggregate value. This method is called at statement execution time. It is usually called once for each row, but if the expression is used multiple times (for example in the column list, and as part of the HAVING expression) it is called multiple times - the row counter needs to be used to make sure the internal state is only updated once.

指定者:

updateAggregate 在类中 Expression

参数:

session - the session

isEverything

public boolean isEverything(ExpressionVisitor visitor)

从类复制的说明: Expression

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 Expression

参数:

visitor - the visitor

返回:

if the criteria can be fulfilled

getCost

public int getCost()

从类复制的说明: Expression

Estimate the cost to process the expression. Used when optimizing the query, to calculate the query plan with the lowest estimated cost.

指定者:

getCost 在类中 Expression

返回:

the estimated cost

createIndexConditions

public void createIndexConditions(Session session,
                                  TableFilter filter)

从类复制的说明: Expression

Create index conditions if possible and attach them to the table filter.

覆盖:

createIndexConditions 在类中 Expression

参数:

session - the session

filter - the table filter

getType

public int getType()

从类复制的说明: Expression

Return the data type. The data type may not be known before the optimization phase.

指定者:

getType 在类中 Expression

返回:

the type

getScale

public int getScale()

从类复制的说明: Expression

Get the scale of this expression.

指定者:

getScale 在类中 Expression

返回:

the scale

getPrecision

public long getPrecision()

从类复制的说明: Expression

Get the precision of this expression.

指定者:

getPrecision 在类中 Expression

返回:

the precision

getDisplaySize

public int getDisplaySize()

从类复制的说明: Expression

Get the display size of this expression.

指定者:

getDisplaySize 在类中 Expression

返回:

the display size