org.h2.expression.condition

类 ConditionAndOr

java.lang.Object

org.h2.expression.Expression

org.h2.expression.condition.ConditionAndOr

所有已实现的接口:

HasSQL, Typed

public class ConditionAndOr
extends Expression

An 'and' or 'or' condition as in WHERE ID=1 AND NAME=?

字段概要

字段

限定符和类型	字段和说明
static int	AND The AND condition type as in ID=1 AND NAME='Hello'.
static int	OR The OR condition type as in ID=1 OR NAME='Hello'.

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
ConditionAndOr(int andOrType, Expression left, Expression right)

方法概要

限定符和类型	方法和说明
void	addFilterConditions(TableFilter filter) Add conditions to a table filter if they can be evaluated.
void	createIndexConditions(SessionLocal session, TableFilter filter) Create index conditions if possible and attach them to the table filter.
int	getCost() Estimate the cost to process the expression.
Expression	getNotIfPossible(SessionLocal session) If it is possible, return the negated expression.
Expression	getSubexpression(int index) Returns subexpression with specified index.
int	getSubexpressionCount() Returns count of subexpressions.
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.
void	mapColumns(ColumnResolver resolver, int level, int state) Map the columns of the resolver to expression columns.
boolean	needParentheses() Returns whether this expressions needs to be wrapped in parentheses when it is used as an argument of other expressions.
Expression	optimize(SessionLocal 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(SessionLocal session, int stage) Update an aggregate value.

从类继承的方法 org.h2.expression.Expression

getAlias, getBooleanValue, getColumnName, getColumnNameForView, getEnclosedSQL, getNonAliasExpression, getNullable, getSchemaName, getSQL, getSQL, getSQL, getSQL, getTableAlias, getTableName, getWhenSQL, getWhenValue, isConstant, isIdentity, isNullConstant, isValueSet, isWhenConditionOperand, 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

字段详细资料

AND

public static final int AND

The AND condition type as in ID=1 AND NAME='Hello'.

另请参阅:

常量字段值

OR

public static final int OR

The OR condition type as in ID=1 OR NAME='Hello'.

另请参阅:

常量字段值

构造器详细资料

ConditionAndOr

public ConditionAndOr(int andOrType,
                      Expression left,
                      Expression right)

方法详细资料

needParentheses

public boolean needParentheses()

从类复制的说明: Expression

Returns whether this expressions needs to be wrapped in parentheses when it is used as an argument of other expressions.

覆盖:

needParentheses 在类中 Expression

返回:

true if it is

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

createIndexConditions

public void createIndexConditions(SessionLocal 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

getNotIfPossible

public Expression getNotIfPossible(SessionLocal session)

从类复制的说明: Expression

If it is possible, return the negated expression. This is used to optimize NOT expressions: NOT ID>10 can be converted to ID<=10. Returns null if negating is not possible.

覆盖:

getNotIfPossible 在类中 Expression

参数:

session - the session

返回:

the negated expression, or null

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

optimize

public Expression optimize(SessionLocal 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

addFilterConditions

public void addFilterConditions(TableFilter filter)

从类复制的说明: Expression

Add conditions to a table filter if they can be evaluated.

覆盖:

addFilterConditions 在类中 Expression

参数:

filter - the table filter

mapColumns

public void mapColumns(ColumnResolver resolver,
                       int level,
                       int state)

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

state - current state for nesting checks, initial value is Expression.MAP_INITIAL

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

updateAggregate

public void updateAggregate(SessionLocal session,
                            int stage)

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

stage - select stage

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

getSubexpressionCount

public int getSubexpressionCount()

从类复制的说明: Expression

Returns count of subexpressions.

覆盖:

getSubexpressionCount 在类中 Expression

返回:

count of subexpressions

getSubexpression

public Expression getSubexpression(int index)

从类复制的说明: Expression

Returns subexpression with specified index.

覆盖:

getSubexpression 在类中 Expression

参数:

index - 0-based index

返回:

subexpression with specified index, may be null

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