Package org.apache.empire.db.expr.column

Class DBCaseExpr

java.lang.Object

org.apache.empire.db.DBObject

org.apache.empire.db.DBExpr

org.apache.empire.db.DBColumnExpr

org.apache.empire.db.expr.column.DBCaseExpr

All Implemented Interfaces:

ColumnExpr

Direct Known Subclasses:

DBCaseMapExpr, DBCaseWhenExpr

public abstract class DBCaseExpr
extends DBColumnExpr

This class represents a SQL case expression like "case when ?=A then X else Y end" or "case ? when A then X else Y end"

This abstract class is implemented by DBCaseMapExpr and DBCaseWhenExpr

Author:

doebele

Field Summary

Fields inherited from class org.apache.empire.db.DBColumnExpr

attributes, beanPropertyName, options

Fields inherited from class org.apache.empire.db.DBExpr

CTX_ALIAS, CTX_ALL, CTX_DEFAULT, CTX_FULLNAME, CTX_NAME, CTX_NOPARENTHESIS, CTX_VALUE

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	DBCaseExpr(DBColumnExpr caseExpr)
protected	DBCaseExpr(DBDatabase db)

Method Summary

Modifier and Type	Method	Description
Element	addXml(Element parent, long flags)	Add a description of this column with relevant metadata to the supplied parent XML Element.
final DBDatabase	getDatabase()	Returns the database object to which this object belongs to.
DataType	getDataType()	Returns the data type of this column expression.
Class<Enum<?>>	getEnumType()	Returns the enum type for this column
DBRowSet	getRowSet()	Returns the underlying rowset containing this column For functions involving none or more than one physical column this function return the first one
protected DBColumnExpr	getSourceColumnExpr(Collection<?> values, Object elseValue)
DBColumn	getUpdateColumn()	Returns the underlying physical column.
protected void	init(Map<?,?> valueMap, Object elseValue)	Init case expression.
protected void	initDataTypeFromValue(Object value)
boolean	isAggregate()	Indicates whether this function is an aggregate (sum, min, max, avg, ...) or not
protected boolean	isNotNull(Object value)	helper to check if an expression is not null
protected boolean	isNull(Object value)	helper to check if an expression is null

Methods inherited from class org.apache.empire.db.DBColumnExpr

abs, aggregate, append, as, as, asc, avg, ceiling, cmp, coalesce, concat, concat, contains, convertTo, convertTo, count, countDistinct, day, decode, decode, decode, decode, decode, decode, decodeEnum, decodeSort, desc, divideBy, floor, format, function, getAttribute, getAttribute, getBeanPropertyName, getControlType, getDefaultSortOrder, getExprFromPhrase, getExprFromPhrase, getIgnoreCaseExpr, getJavaType, getName, getNumberType, getOptions, getSourceColumn, getTitle, in, in, in, indexOf, indexOf, indexOf, is, isBetween, isCaseSensitive, isGreaterThan, isLessOrEqual, isLiteralValue, isMoreOrEqual, isNot, isNotBetween, isSmallerThan, length, like, like, likeLower, likeUpper, lower, max, min, minus, minus, modulo, month, multiplyWith, notContains, notIn, notIn, notIn, notLike, nvl, on, parenthesis, plus, plus, prepend, qualified, replace, reverse, round, setAttribute, setBeanPropertyName, setControlType, setDefaultSortOrder, setOptions, setTitle, stringAgg, stringAgg, substring, substring, substring, substring, substring, substring, sum, toChar, toChar, toString, trim, trimLeft, trimRight, trunc, upper, when, year

Methods inherited from class org.apache.empire.db.DBExpr

addReferencedColumns, addSQL

Methods inherited from class org.apache.empire.db.DBObject

checkParamNull

Methods inherited from class java.lang.Object

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

Constructor Details

DBCaseExpr

protected DBCaseExpr(DBDatabase db)

DBCaseExpr

protected DBCaseExpr(DBColumnExpr caseExpr)

Method Details

getDatabase

public final DBDatabase getDatabase()

Description copied from class: DBObject

Returns the database object to which this object belongs to. For the database object itself this function will return the this pointer.

Specified by:

getDatabase in class DBObject

Returns:

the database object

getDataType

public DataType getDataType()

Description copied from class: DBColumnExpr

Returns the data type of this column expression.

Specified by:

getDataType in interface ColumnExpr

Specified by:

getDataType in class DBColumnExpr

Returns:

the expressions data type

See Also:

• DataType

getEnumType

public Class<Enum<?>> getEnumType()

Description copied from interface: ColumnExpr

Returns the enum type for this column

Returns:

the enum type

getRowSet

public DBRowSet getRowSet()

Description copied from class: DBColumnExpr

Returns the underlying rowset containing this column For functions involving none or more than one physical column this function return the first one

Specified by:

getRowSet in class DBColumnExpr

Returns:

a column used for this expression

getUpdateColumn

public DBColumn getUpdateColumn()

Description copied from class: DBColumnExpr

Returns the underlying physical column. For functions involving none or more than one physical column this function returns null.

Specified by:

getUpdateColumn in interface ColumnExpr

Specified by:

getUpdateColumn in class DBColumnExpr

Returns:

the underlying column

isAggregate

public boolean isAggregate()

Description copied from class: DBColumnExpr

Indicates whether this function is an aggregate (sum, min, max, avg, ...) or not

Specified by:

isAggregate in class DBColumnExpr

Returns:

true if the column expression represents an aggregate

addXml

public Element addXml(Element parent,
 long flags)

Description copied from class: DBColumnExpr

Add a description of this column with relevant metadata to the supplied parent XML Element.

Specified by:

addXml in class DBColumnExpr

Parameters:

parent - the parent element to which to append the column description

flags - currently not used

Returns:

the newly created child element

isNull

protected boolean isNull(Object value)

helper to check if an expression is null

Parameters:

value - the value to check

Returns:

true if null or false otherwise

isNotNull

protected boolean isNotNull(Object value)

helper to check if an expression is not null

Parameters:

value - the value

Returns:

true if not null or false otherwise

init

protected void init(Map<?,?> valueMap,
 Object elseValue)

Init case expression. Must be called from all constructors!

Parameters:

valueMap - the value or conditions map

elseValue - the else value

getSourceColumnExpr

protected DBColumnExpr getSourceColumnExpr(Collection<?> values,
 Object elseValue)

initDataTypeFromValue

protected void initDataTypeFromValue(Object value)