Format

java.lang.Object
- org.h2.expression.Expression
- - org.h2.expression.Format

```
public class Format
extends Expression
```
A format clause such as FORMAT JSON.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class Format.FormatEnum
Supported formats.

Nested Classes
Modifier and Type	Class and Description
`static class`	`Format.FormatEnum` Supported formats.

Field Summary
- Fields inherited from class org.h2.expression.Expression
  MAP_IN_AGGREGATE, MAP_IN_WINDOW, MAP_INITIAL

Constructor Summary

Constructors
Constructor and Description

Format(Expression expression, Format.FormatEnum format)

Constructors
Constructor and Description
`Format(Expression expression, Format.FormatEnum format)`

Method Summary

Methods
Modifier and Type	Method and Description
`java.lang.String`	`getColumnName()` Get the column name or alias name of this expression.
`int`	`getCost()` Estimate the cost to process the expression.
`int`	`getNullable()` Check whether this expression is a column and can store NULL.
`java.lang.StringBuilder`	`getSQL(java.lang.StringBuilder builder, boolean alwaysQuote)` Appends the SQL statement of this expression to the specified builder.
`Expression`	`getSubexpression(int index)` Returns subexpression with specified index.
`int`	`getSubexpressionCount()` Returns count of subexpressions.
`java.lang.String`	`getTableName()` Get the table name, or null
`TypeInfo`	`getType()` Returns the data type.
`Value`	`getValue(Session session)` Return the resulting value for the current row.
`Value`	`getValue(Value value)` Returns the value with applied format.
`boolean`	`isAutoIncrement()` Check if this is an auto-increment column.
`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.
`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, int stage)` Update an aggregate value.

Methods inherited from class org.h2.expression.Expression
addFilterConditions, createIndexConditions, getAlias, getBooleanValue, getExpressionColumns, getExpressionColumns, getExpressionColumns, getNonAliasExpression, getNotIfPossible, getSchemaName, getSQL, getTableAlias, getUnenclosedSQL, isConstant, isNullConstant, isValueSet, toString, writeExpressions, writeExpressions

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - Format
```
public Format(Expression expression,
      Format.FormatEnum format)
```
- Method Detail
  - getValue
```
public Value getValue(Session session)
```
    Description copied from class: Expression
    
    Return the resulting value for the current row.
    
    Specified by:
    
    getValue in class Expression
    
    Parameters:
    session - the session
    
    Returns:
    the result
  - getValue
```
public Value getValue(Value value)
```
    Returns the value with applied format.
    
    Parameters:
    value - the value
    
    Returns:
    the value with applied format
  - getType
```
public TypeInfo getType()
```
    Description copied from class: Expression
    
    Returns the data type. The data type may not be known before the optimization phase.
    
    Specified by:
    
    getType in class Expression
    
    Returns:
    the data type
  - mapColumns
```
public void mapColumns(ColumnResolver resolver,
              int level,
              int state)
```
    Description copied from class: Expression
    
    Map the columns of the resolver to expression columns.
    
    Specified by:
    
    mapColumns in class Expression
    
    Parameters:
    resolver - the column resolver
    level - the subquery nesting level
    state - current state for nesting checks, initial value is Expression.MAP_INITIAL
  - optimize
```
public Expression optimize(Session session)
```
    Description copied from class: Expression
    
    Try to optimize the expression.
    
    Specified by:
    
    optimize in class Expression
    
    Parameters:
    session - the session
    
    Returns:
    the optimized expression
  - setEvaluatable
```
public void setEvaluatable(TableFilter tableFilter,
                  boolean b)
```
    Description copied from class: Expression
    
    Tell the expression columns whether the table filter can return values now. This is used when optimizing the query.
    
    Specified by:
    
    setEvaluatable in class Expression
    
    Parameters:
    tableFilter - the table filter
    b - true if the table filter can return value
  - isAutoIncrement
```
public boolean isAutoIncrement()
```
    Description copied from class: Expression
    
    Check if this is an auto-increment column.
    
    Overrides:
    
    isAutoIncrement in class Expression
    
    Returns:
    true if it is an auto-increment column
  - getSQL
```
public java.lang.StringBuilder getSQL(java.lang.StringBuilder builder,
                             boolean alwaysQuote)
```
    Description copied from class: Expression
    
    Appends the SQL statement of this expression to the specified builder. This may not always be the original SQL statement, specially after optimization.
    
    Specified by:
    
    getSQL in class Expression
    
    Parameters:
    builder - string builder
    alwaysQuote - quote all identifiers
    
    Returns:
    the specified string builder
  - updateAggregate
```
public void updateAggregate(Session session,
                   int stage)
```
    Description copied from class: 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.
    
    Specified by:
    
    updateAggregate in class Expression
    
    Parameters:
    session - the session
    stage - select stage
  - getNullable
```
public int getNullable()
```
    Description copied from class: Expression
    
    Check whether this expression is a column and can store NULL.
    
    Overrides:
    
    getNullable in class Expression
    
    Returns:
    whether NULL is allowed
  - isEverything
```
public boolean isEverything(ExpressionVisitor visitor)
```
    Description copied from class: Expression
    
    Check if this expression and all sub-expressions can fulfill a criteria. If any part returns false, the result is false.
    
    Specified by:
    
    isEverything in class Expression
    
    Parameters:
    visitor - the visitor
    
    Returns:
    if the criteria can be fulfilled
  - getCost
```
public int getCost()
```
    Description copied from class: Expression
    
    Estimate the cost to process the expression. Used when optimizing the query, to calculate the query plan with the lowest estimated cost.
    
    Specified by:
    
    getCost in class Expression
    
    Returns:
    the estimated cost
  - getTableName
```
public java.lang.String getTableName()
```
    Description copied from class: Expression
    
    Get the table name, or null
    
    Overrides:
    
    getTableName in class Expression
    
    Returns:
    the table name
  - getColumnName
```
public java.lang.String getColumnName()
```
    Description copied from class: Expression
    
    Get the column name or alias name of this expression.
    
    Overrides:
    
    getColumnName in class Expression
    
    Returns:
    the column name
  - getSubexpressionCount
```
public int getSubexpressionCount()
```
    Description copied from class: Expression
    
    Returns count of subexpressions.
    
    Overrides:
    
    getSubexpressionCount in class Expression
    
    Returns:
    count of subexpressions
  - getSubexpression
```
public Expression getSubexpression(int index)
```
    Description copied from class: Expression
    
    Returns subexpression with specified index.
    
    Overrides:
    
    getSubexpression in class Expression
    
    Parameters:
    index - 0-based index
    
    Returns:
    subexpression with specified index, may be null

Class Format

Nested Class Summary

Field Summary

Fields inherited from class org.h2.expression.Expression

Constructor Summary

Method Summary

Methods inherited from class org.h2.expression.Expression

Methods inherited from class java.lang.Object

Constructor Detail

Format

Method Detail

getValue

getValue

getType

mapColumns

optimize

setEvaluatable

isAutoIncrement

getSQL

updateAggregate

getNullable

isEverything

getCost

getTableName

getColumnName

getSubexpressionCount

getSubexpression