when.md

When / Conditionals

If you store the builder object in a variable, you can use if and else statements like you would expect.

{% code title="QueryBuilder" %}

var q = query.from( "posts" );
if ( someFlag ) {
    q.orderBy( "published_date", "desc" );
}

{% endcode %}

This works, but breaks chainability. To keep chainability you can use the when helper method.

when

Name	Type	Required	Default	Description
condition	boolean	true		The condition to switch on.
onTrue	Function	true		The callback to execute if the condition is true. It is passed the builder object as the only parameter.
onFalse	Function	false	function( q ) { return q; }	The callback to execute if the conditions is false. It is passed the builder object as the only parameter.
withoutScoping	boolean	false	false	Flag to turn off the automatic scoping of where clauses during the callback.

The when helper is used to allow conditional statements when defining queries without using if statements and having to store temporary variables.

{% code title="QueryBuilder" %}

query.from( "posts" )
    .when( someFlag, function( q ) {
        q.orderBy( "published_date", "desc" );
    } )
    .get();

{% endcode %}

You can pass a third argument to be called in the else case.

{% code title="QueryBuilder" %}

query.from( "posts" )
    .when(
        someFlag,
        function( q ) {
            q.orderBy( "published_date", "desc" );
        },
        function( q ) {
            q.orderBy( "modified_date", "desc" );
        }
    );

{% endcode %}

when callbacks are automatically scoped and grouped. That means that if a where clause is added inside the callback with an OR combinator the clauses will automatically be grouped (have parenthesis put around them.) You can disable this feature by passing withoutScoping = true to the when callback.

qb.from( "users" )
    .where( "active", 1 )
    .when( len( url.q ), function( q ) {
        q.where( "username", "LIKE", q & "%" )
            .orWhere( "email", "LIKE", q & "%" );   
    } );

SELECT *
FROM "users"
WHERE "active" = ?
    AND (
        "username" = ?
        OR "email" = ?
    )