Package ece.ing3.java.projet.database.sql.clauses

Class Where

java.lang.Object

ece.ing3.java.projet.database.sql.clauses.Where

public class Where
extends Object

Where clause helper.

Provides a convenient way to build Where clause, reactive-style. Supports where clause nesting.

Where clauses can be chained using either and(Where) and or(Where), depending on the desired operator.

Each and(Where) and or(Where) have shortcut methods, respectively and(String, String, Object) and or(String, String, Object), to avoid creating new unnecessary Where clauses.

Nesting is supported by simply chaining another Where clause.
( new Where( "col1", "=", "val1" ) ).or( ( new Where( "col2", "{@literal <}", "val2" ) ).and( "col3", "{@literal >=}", "val3" ) ).toString();
will generate : (col1 = 'val1' OR ((col2 {@literal <} 'val2') AND (col3 {@literal >=} 'val3')))

Where supports Reactive-style programming to create more compact code.
As such,

 Where o = new Where( "col1", "=", "val1" );
 o.and( "col2", "<", "val2" );
 String v = o.toString();
 

can be written

 String v = ( new Where( "col1", "=", "val1" ) ).and( "col2", "<", "val2" ).toString();
 

Nesting is still supported when using reactive-style programming.

Author:

Virgile, Nicolas, Louis-Félix

Constructor Summary

Constructors

Constructor	Description
Where()	Creates a new chainable, empty Where clause.
Where(String column, String comparator, SQLRequest subquery)	Creates a new chainable Where clause with a subquery.
Where(String column, String comparator, Object value)	Creates a new chainable Where clause.

Method Summary

Modifier and Type	Method	Description
Where	and(Where condition)	Chain a new where clause using the boolean AND.
Where	and(String column, String comparator, SQLRequest subquery)	Chain a new where clause using the boolean AND, using the provided values and subquery.
Where	and(String column, String comparator, Object value)	Chain a new where clause using the boolean AND, using the provided values.
List<Object>	getParameters()	Gets the parameters to use in the prepared statement.
Object[]	getParametersArray()	Gets the parameters to use in the prepared statement.
Where	or(Where condition)	Chain a new where clause using the boolean OR.
Where	or(String column, String comparator, SQLRequest subquery)	Chain a new where clause using the boolean OR, using the provided values and subquery.
Where	or(String column, String comparator, Object value)	Chain a new where clause using the boolean OR, using the provided values.
String	toString()	Gets the corresponding SQL Where clause, for use in a prepared statement.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Details

Where

public Where()

Creates a new chainable, empty Where clause.

Where

public Where(String column,
 String comparator,
 Object value)

Creates a new chainable Where clause.

Parameters:

column - Column to target

comparator - Comparator to use

value - Comparison value

Where

public Where(String column,
 String comparator,
 SQLRequest subquery)

Creates a new chainable Where clause with a subquery.

Parameters:

column - Column to target

comparator - Comparator to use

subquery - Sub query

Method Details

and

public Where and(Where condition)

Chain a new where clause using the boolean AND.

Parameters:

condition - Where clause to chain

Returns:

This Where clause helper

or

public Where or(Where condition)

Chain a new where clause using the boolean OR.

Parameters:

condition - Where clause to chain

Returns:

This Where clause helper

and

public Where and(String column,
 String comparator,
 Object value)

Chain a new where clause using the boolean AND, using the provided values.

Parameters:

column - Column to target

comparator - Comparator to use

value - Comparison value

Returns:

This Where clause helper

or

public Where or(String column,
 String comparator,
 Object value)

Chain a new where clause using the boolean OR, using the provided values.

Parameters:

column - Column to target

comparator - Comparator to use

value - Comparison value

Returns:

This Where clause helper

and

public Where and(String column,
 String comparator,
 SQLRequest subquery)

Chain a new where clause using the boolean AND, using the provided values and subquery.

Parameters:

column - Column to target

comparator - Comparator to use

subquery - Sub query

Returns:

This Where clause helper

or

public Where or(String column,
 String comparator,
 SQLRequest subquery)

Chain a new where clause using the boolean OR, using the provided values and subquery.

Parameters:

column - Column to target

comparator - Comparator to use

subquery - Sub query

Returns:

This Where clause helper

toString

public String toString()

Gets the corresponding SQL Where clause, for use in a prepared statement.

Overrides:

toString in class Object

Returns:

SQL Order By clause

getParameters

public List<Object> getParameters()

Gets the parameters to use in the prepared statement.

Returns:

Statement parameters

getParametersArray

public Object[] getParametersArray()

Gets the parameters to use in the prepared statement.

Returns:

Statement parameters