org.h2.expression

类 Variable

java.lang.Object

org.h2.expression.Expression

org.h2.expression.Operation0

org.h2.expression.Variable

所有已实现的接口:

HasSQL, Typed

public final class Variable
extends Operation0

A user-defined variable, for example: @ID.

字段概要

从类继承的字段 org.h2.expression.Expression

AUTO_PARENTHESES, MAP_IN_AGGREGATE, MAP_IN_WINDOW, MAP_INITIAL, WITH_PARENTHESES, WITHOUT_PARENTHESES

从接口继承的字段 org.h2.util.HasSQL

ADD_PLAN_INFORMATION, DEFAULT_SQL_FLAGS, NO_CASTS, QUOTE_ONLY_WHEN_REQUIRED, REPLACE_LOBS_FOR_TRACE, TRACE_SQL_FLAGS

构造器概要

构造器

构造器和说明
Variable(SessionLocal session, String name)

方法概要

限定符和类型	方法和说明
int	getCost() Estimate the cost to process the expression.
String	getName()
TypeInfo	getType() Returns the data type.
StringBuilder	getUnenclosedSQL(StringBuilder builder, int sqlFlags) Get the SQL statement of this expression.
Value	getValue(SessionLocal 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.

从类继承的方法 org.h2.expression.Operation0

mapColumns, optimize, setEvaluatable, updateAggregate

从类继承的方法 org.h2.expression.Expression

addFilterConditions, createIndexConditions, getAlias, getBooleanValue, getColumnName, getColumnNameForView, getEnclosedSQL, getNonAliasExpression, getNotIfPossible, getNullable, getSchemaName, getSQL, getSQL, getSQL, getSQL, getSubexpression, getSubexpressionCount, getTableAlias, getTableName, getWhenSQL, getWhenValue, isConstant, isIdentity, isNullConstant, isValueSet, isWhenConditionOperand, needParentheses, optimizeCondition, toString, writeExpressions, writeExpressions

从类继承的方法 java.lang.Object

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

从接口继承的方法 org.h2.util.HasSQL

getTraceSQL

构造器详细资料

Variable

public Variable(SessionLocal session,
                String name)

方法详细资料

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

getUnenclosedSQL

public StringBuilder getUnenclosedSQL(StringBuilder builder,
                                      int sqlFlags)

从类复制的说明: Expression

Get the SQL statement of this expression. This may not always be the original SQL statement, especially after optimization. Enclosing '(' and ')' are never appended.

指定者:

getUnenclosedSQL 在类中 Expression

参数:

builder - string builder

sqlFlags - formatting flags

返回:

the specified string builder

getType

public TypeInfo getType()

从类复制的说明: Expression

Returns the data type. The data type may be unknown before the optimization phase.

指定者:

getType 在接口中 Typed

指定者:

getType 在类中 Expression

返回:

the data type

getValue

public Value getValue(SessionLocal 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

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

getName

public String getName()