Thread: Need help with relational query

How can I add a WHERE clause in my query (see below) to select only the Project results WHERE the Communications.createdbyid is according to a result?

The parallel MySQL example I am trying to get is:
SELECT * FROM Project_info__c INNER JOIN Communicatiions__c ON (Project_info__c.id = Communicatiions__c.id) WHERE Communicatiions__c.createdbyid = 'some date'

Code:

<complexType name="Project_info__c">
    <complexContent>
        <extension base="ens:sObject">
            <sequence>   
            <...cut...>                     
            <element name="Communications__r" nillable="true" minOccurs="0" type="tns:QueryResult"/>
            <...cut...>                     
            </sequence>
        </extension>
    </complexContent>
</complexType>
 
=======================================
 
<complexType name="Communicatiions__c">
    <complexContent>
        <extension base="ens:sObject">
            <sequence>
            <...cut...>                     
            <element name="CreatedById" nillable="true" minOccurs="0" type="tns:ID"/>
            <...cut...>                     
            </sequence>
        </extension>
    </complexContent>
</complexType>
 
============================
 
php:
$query = "SELECT 
                                Id,
                                Name,
                                Status__c ,                             
                                (SELECT Name,CreatedById FROM Communications__r),                               
                                FROM Project_info__c 
                                ";