SOQL

SOQL Queries:

SOQL can be used in the following areas:

1. In the queryString parameter  in  the query call.
2. In the Apex Statements.
3. In the Visualforce controllers and getter methods.
4. In the Schema Explorer of the Force.com IDE.

Syntax of SOQL:

 

SELECT one or more fields

FROM  an object

WHERE filter statements and, optionally, results are ordered.

Example: SELECT id,name from Account where name='Naveen'

Using Alias notation in SOQL:

Select id,name from Contact c,c.Account a where a.name='Wipro'

• The above query returns the contacts whose account name is 'Wipro'.
• SOQL keywords can't be used as alias names.

SOQL Keywords:

1. AND
2. ASC
3. DESC
4. EXCLUDES
5. FIRST
6. FROM
7. GROUP
8. HAVING
9. IN 
10. INCLUDES
11. LAST 
12. LIKE 
13. LIMIT
14. NOT 
15. NULL
16. NULLS
17. OR
18. SELECT 
19. WHERE 
20. WITH

Reserved Characters of SOQL:

'(single quote) and \(back slash) are reserved characters in SOQL

For Example to Query the Account name field for "Naveen's Enclave", use the following syntax.

SELECT Id,Name

FROM Account 

WHERE Name Like 'Naveen\'s Enclave'

Implementation Tips:

• By Default SOQL Statements can't exceed 20k characters. For SOQL Statements Exceed this length, the API returns MALFORMED_QUERY Exception code; no result rows are returned.
• Select Statements can include the toLabel() and convertCurrency() functions in support of localization fields.
• Apex Script variables and expressions can be used if preceded by a column(:).
• There is no guarantee of the order of results unless you use an ORDER BY clause in a query.