am not a Salesforce Apex developer but I have managed to implement the apex pages and classes for Advanced opportunity search on our SandBox environment and it is working fine but when I try to upload to the live environment using Change Set of Salesforce, then it is not going through and producing following message.

“Average test coverage across all Apex Classes and Triggers is 65%, at least 75% test coverage is required.”

I have done some research on Salesforce community forum about this but could not fix this. Can you please help us to upload this to the live environment with maximum test coverage? I do not know how to write the tests for the apex classes. Could you please help me write this for the following classes.

I got the coding from Jeff Douglas website blog and then customised according to my environment.

http://blog.jeffdouglas.com/2010/07/13/building-a-dynamic-search-page-in-visualforce/

here is my apex class

public with sharing class CustomSearchController {
 
  // the soql without the order and limit
  private String soql {get;set;}
  // the collection of contacts to display
  public List<Opportunity> opportunities {get;set;}
 
  // the current sort direction. defaults to asc
  public String sortDir {
    get  { if (sortDir == null) {  sortDir = 'asc'; } return sortDir;  }
    set;
  }
 
  // the current field to sort by. defaults to last name
  public String sortField {
    get  { if (sortField == null) {sortField = 'Name'; } return sortField;  }
    set;
  }
 
  // format the soql for display on the visualforce page
  public String debugSoql {
    get { return soql + ' order by ' + sortField + ' ' + sortDir + ' limit 100'; }
    set;
  }
 
  // init the controller and display some sample data when the page loads
  public CustomSearchController() {
    soql = 'select id, name, cohort__c, Component_Module__c, account.name, Start_of_Programme__c, End_of_Programme__c from opportunity where account.name != null';
    runQuery();
  }
 
  // toggles the sorting of query from asc<-->desc
  public void toggleSort() {
    // simply toggle the direction
    sortDir = sortDir.equals('asc') ? 'desc' : 'asc';
    // run the query again
    runQuery();
  }
 
  // runs the actual query
  public void runQuery() {
 
    try {
      opportunities = Database.query(soql + ' order by ' + sortField + ' ' + sortDir + ' limit 100');
    } catch (Exception e) {
      ApexPages.addMessage(new ApexPages.Message(ApexPages.Severity.ERROR, 'Ooops!'));
    }
 
  }
 
  // runs the search with parameters passed via Javascript
  public PageReference runSearch() {
 
    String opportunityName = Apexpages.currentPage().getParameters().get('opportunityName');
    String cohort = Apexpages.currentPage().getParameters().get('cohort');
    String accountName = Apexpages.currentPage().getParameters().get('accountName');
 
    soql = 'select id, name, cohort__c, Component_Module__c, account.name, Start_of_Programme__c, End_of_Programme__c from opportunity where account.name != null';

    if (!opportunityName.equals(''))
      soql += ' and name LIKE \'%'+String.escapeSingleQuotes(opportunityName)+'%\'';

    if (!cohort.equals(''))
      soql += ' and cohort__c LIKE \''+String.escapeSingleQuotes(cohort)+'\'';

    if (!accountName.equals(''))
      soql += ' and account.name LIKE \''+String.escapeSingleQuotes(accountName)+'%\'';  
 
    // run the query again
    runQuery();
 
    return null;
  }
 
}

and my apex page

<apex:page controller="CustomSearchController" sidebar="false">
 
  <apex:form >
  <apex:pageMessages id="errors" />
 
  <apex:pageBlock title="Search Opportunities" mode="edit">
 
  <table width="100%" border="0">
  <tr>  
    <td width="200" valign="top">
 
      <apex:pageBlock title="Parameters" mode="edit" id="criteria">
 
      <script type="text/javascript">
      function doSearch() {
        searchServer(
          document.getElementById("opportunityName").value,
          document.getElementById("cohort").value,
          document.getElementById("accountName").value,
          ''
          );
      }
      </script> 
 
      <apex:actionFunction name="searchServer" action="{!runSearch}" rerender="results,debug,errors">
          <apex:param name="opportunityName" value="" />
          <apex:param name="cohort" value="" />
          <apex:param name="accountName" value="" />
      </apex:actionFunction>
 
      <table cellpadding="2" cellspacing="2">
      <tr>
        <td style="font-weight:bold;">Opportunity Name<br/>
        <input type="text" id="opportunityName" onkeyup="doSearch();"/>
        </td>
      </tr>
      <tr>
        <td style="font-weight:bold;">Cohort<br/>
        <input type="text" id="cohort" onkeyup="doSearch();"/>
        </td>
      </tr>
      <tr>
        <td style="font-weight:bold;">Client<br/>
        <input type="text" id="accountName" onkeyup="doSearch();"/>
        </td>
      </tr>
      </table>
 
      </apex:pageBlock>
 
    </td>
    <td valign="top">
 
    <apex:pageBlock mode="edit" id="results">
 
        <apex:pageBlockTable value="{!opportunities}" var="opportunity">
 
            <apex:column >
                <apex:facet name="header">
                    <apex:commandLink value="Opportunity Name" action="{!toggleSort}" rerender="results,debug">
                        <apex:param name="sortField" value="opportunityName" assignTo="{!sortField}"/>
                    </apex:commandLink>
                </apex:facet>
                <apex:outputLink value="/{!opportunity.Id}" id="opportunity_id">
                    <apex:outputField value="{!opportunity.name}"/>
                </apex:outputLink>
            </apex:column>
 
            <apex:column >
                <apex:facet name="header">
                    <apex:commandLink value="Cohort" action="{!toggleSort}" rerender="results,debug">
                        <apex:param name="sortField" value="cohort" assignTo="{!sortField}"/>
                    </apex:commandLink>
                </apex:facet>
                <apex:outputField value="{!opportunity.Cohort__c}"/>
            </apex:column>
 
            <apex:column >
                <apex:facet name="header">
                    <apex:commandLink value="Module/Component" action="{!toggleSort}" rerender="results,debug">
                        <apex:param name="sortField" value="Component_Module" assignTo="{!sortField}"/>
                    </apex:commandLink>
                </apex:facet>
                <apex:outputField value="{!opportunity.Component_Module__c}"/>
            </apex:column>
 
            <apex:column >
                <apex:facet name="header">
                    <apex:commandLink value="Client" action="{!toggleSort}" rerender="results,debug">
                        <apex:param name="sortField" value="account.name" assignTo="{!sortField}"/>
                    </apex:commandLink>
                </apex:facet>
                <apex:outputField value="{!opportunity.account.name}"/>
            </apex:column>
 
            <apex:column >
                <apex:facet name="header">
                    <apex:commandLink value="Programme Start Date" action="{!toggleSort}" rerender="results,debug">
                        <apex:param name="sortField" value="programme_start_date" assignTo="{!sortField}"/>
                    </apex:commandLink>
                </apex:facet>
                <apex:outputField value="{!opportunity.Start_of_Programme__c}"/>
            </apex:column>

            <apex:column >
                <apex:facet name="header">
                    <apex:commandLink value="Programme End Date" action="{!toggleSort}" rerender="results,debug">
                        <apex:param name="sortField" value="programme_end_date" assignTo="{!sortField}"/>
                    </apex:commandLink>
                </apex:facet>
                <apex:outputField value="{!opportunity.End_of_Programme__c}"/>
            </apex:column>
 
 
        </apex:pageBlockTable>
 
    </apex:pageBlock>
 
    </td>
  </tr>
  </table>
 
 
  </apex:pageBlock>
 
  </apex:form>
 
</apex:page>