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

Class DBFuncExpr

java.lang.Object

org.apache.empire.db.DBObject

org.apache.empire.db.DBExpr

org.apache.empire.db.DBColumnExpr

org.apache.empire.db.expr.column.DBAbstractFuncExpr

org.apache.empire.db.expr.column.DBFuncExpr

All Implemented Interfaces:

ColumnExpr, DBPreparable

public class DBFuncExpr
extends DBAbstractFuncExpr

This class is used for performing various SQL functions on a column or column expression.

There is no need to explicitly create instances of this class.
Instead use any of the following functions:
DBColumnExpr.abs(), DBColumnExpr.coalesce(Object), DBColumnExpr.convertTo(DataType), DBColumnExpr.decode(java.util.Map, Object), DBColumnExpr.lower(), DBColumnExpr.min(), DBColumnExpr.max(), DBColumnExpr.month(), DBColumnExpr.sum(), DBColumnExpr.trim(), DBColumnExpr.upper(), DBColumnExpr.year()

Field Summary

Fields

Modifier and Type	Field	Description
protected final Object[]	params
protected final DBSqlPhrase	phrase
protected String	template

Fields inherited from class org.apache.empire.db.expr.column.DBAbstractFuncExpr

dataType, expr, isAggregate, log

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

Constructor	Description
DBFuncExpr(DBColumnExpr expr, String template, Object[] params, boolean isAggregate, DataType dataType)	Constructs a new DBFuncExpr object set the specified parameters to this object.
DBFuncExpr(DBColumnExpr expr, DBSqlPhrase phrase, Object[] params, DataType dataType)	Constructs a new DBFuncExpr object set the specified parameters to this object.

Method Summary

Modifier and Type	Method	Description
void	addReferencedColumns(Set<DBColumn> list)	Internal function to obtain all DBColumnExpr-objects used by this expression.
void	addSQL(DBSQLBuilder sql, long context)	Creates the SQL-Command adds a function to the SQL-Command.
Object	getAttribute(String name)	Returns the value of a column attribute.
Class<Enum<?>>	getEnumType()	Maybe an Enum...
protected String	getFunctionName()	returns the name of the function
DBSqlPhrase	getPhrase()

Methods inherited from class org.apache.empire.db.expr.column.DBAbstractFuncExpr

addSQL, addXml, equals, getDatabase, getDataType, getDbms, getName, getRowSet, getUpdateColumn, isAggregate, prepareParams

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, getBeanPropertyName, getControlType, getDefaultSortOrder, getExprFromPhrase, getExprFromPhrase, getIgnoreCaseExpr, getJavaType, 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.DBObject

checkParamNull

Methods inherited from class java.lang.Object

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

Field Details

phrase

protected final DBSqlPhrase phrase

params

protected final Object[] params

template

protected String template

Constructor Details

DBFuncExpr

public DBFuncExpr(DBColumnExpr expr,
 DBSqlPhrase phrase,
 Object[] params,
 DataType dataType)

Constructs a new DBFuncExpr object set the specified parameters to this object. Do not use directly - use any of the DBColumnExpr.??? factory functions instead! The sql function string is built from a string template. The template string is identified by the phrase param and obtained from the dbms.

Parameters:

expr - the DBColumnExpr object

phrase - the SQL-phrase

params - an array of params which will be replaced in the template

dataType - indicates the data type of the function result

DBFuncExpr

public DBFuncExpr(DBColumnExpr expr,
 String template,
 Object[] params,
 boolean isAggregate,
 DataType dataType)

Constructs a new DBFuncExpr object set the specified parameters to this object. The sql function string is built from a string template. The template string must contain a ? which is a placeholder for the column expression.

Parameters:

expr - the DBColumnExpr object

template - specifies a template for the expression. The template must contain a ? placeholder for the column expression

params - an array of params which will be replaced in the template

isAggregate - indicates whether the function is an aggregate function (sum, min, max, avg, ...)

dataType - indicates the data type of the function result

Method Details

getPhrase

public DBSqlPhrase getPhrase()

getFunctionName

protected String getFunctionName()

Description copied from class: DBAbstractFuncExpr

returns the name of the function

Specified by:

getFunctionName in class DBAbstractFuncExpr

Returns:

the function name

getEnumType

public Class<Enum<?>> getEnumType()

Description copied from class: DBAbstractFuncExpr

Maybe an Enum...

Specified by:

getEnumType in interface ColumnExpr

Overrides:

getEnumType in class DBAbstractFuncExpr

Returns:

the enum type

getAttribute

public Object getAttribute(String name)

Description copied from class: DBColumnExpr

Returns the value of a column attribute. Column attributes are used to provide metadata for a column.

Specified by:

getAttribute in interface ColumnExpr

Overrides:

getAttribute in class DBColumnExpr

Parameters:

name - the attribute name

Returns:

value of the attribute if it exists or null otherwise

addReferencedColumns

public void addReferencedColumns(Set<DBColumn> list)

Description copied from class: DBExpr

Internal function to obtain all DBColumnExpr-objects used by this expression.

Overrides:

addReferencedColumns in class DBAbstractFuncExpr

Parameters:

list - list to which all used column expressions must be added

See Also:

• DBExpr.addReferencedColumns(Set)

addSQL

public void addSQL(DBSQLBuilder sql,
 long context)

Creates the SQL-Command adds a function to the SQL-Command.

Specified by:

addSQL in class DBExpr

Parameters:

sql - the SQL-Command

context - the current SQL-Command context