具有搜索功能是每个业务或应用程序的基本要求之一。为此，Salesforce.com提供了使用SOSL和SOQL的两种主要方法：
SOSL：
在整个对象和字段上搜索文本字符串将通过使用SOSL来完成。这是Salesforce对象搜索语言。它具有在多个对象上搜索特定字符串的能力。SOSL语句评估sObjects的列表，其中每个列表包含特定sObject类型的搜索结果。结果列表始终以与在SOSL查询中指定的顺序相同的顺序返回。
SOQL：
这与SOQL几乎相同。您可以使用它从一个对象只获取一次对象记录。您可以编写嵌套查询，并从您要查询的父对象或子对象获取记录。我们将在本章中学习SOSL。我们将在下一章探讨SOQL。
SOSL查询示例
考虑一个商业案例，我们需要开发一个程序，可以搜索指定的字符串。假设，我们想在Invoice对象的Customer Name字段中搜索字符串'ABC'。代码如下：首先，您必须在Invoice对象中创建一个客户名为“ABC”的记录，以便在搜索时获得有效的结果。
//Program To Search the given string in all Object
//List to hold the returned results of sObject generic type
List<list<SObject>> invoiceSearchList = new List<List<SObject>>();
//SOSL query which will search for 'ABC' string in Customer Name field of Invoice Object
invoiceSearchList = [FIND 'ABC*' IN ALL FIELDS RETURNING APEX_Invoice__c (Id,APEX_Customer__r.Name)];
//Returned result will be printed
System.debug('Search Result '+invoiceSearchList);
//Now suppose, you would like to search string 'ABC' in two objects, that is Invoice and Account. Then for this query goes like this:
//Program To Search the given string in Invoice and Account object, you could specify more objects if you wAnt, create an Account with Name as ABC.
//List to hold the returned results of sObject generic type
List<List<SObject>> invoiceAndSearchList = new List<List<SObject>>();
//SOSL query which will search for 'ABC' string in Invoice and in Account object's fields
invoiceAndSearchList = [FIND 'ABC*' IN ALL FIELDS RETURNING APEX_Invoice__c (Id,APEX_Customer__r.Name), Account];
//Returned result will be printed
System.debug('Search Result '+invoiceAndSearchList);
//This list will hold the returned results for Invoice Object
APEX_Invoice__c [] searchedInvoice = ((List<APEX_Invoice__c>)invoiceAndSearchList[0]);
//This list will hold the returned results for Account Object
Account [] searchedAccount = ((List<Account>)invoiceAndSearchList[1]);
System.debug('Value of searchedInvoice'+searchedInvoice+'Value of searchedAccount'+searchedAccount);