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title: "APPLOCK_TEST (Transact-SQL) | Microsoft Docs"
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---
# APPLOCK_TEST (Transact-SQL)
[!INCLUDE[tsql-appliesto-ss2008-asdb-xxxx-xxx-md](../../includes/tsql-appliesto-ss2008-asdb-xxxx-xxx-md.md)]

This function returns information as to whether or not a lock can be granted on a particular application resource, for a specified lock owner, without acquisition of the lock. As an application lock function, APPLOCK_TEST operates on the current database. The database is the scope of the application locks.
  
![Topic link icon](../../database-engine/configure-windows/media/topic-link.gif "Topic link icon") [Transact-SQL Syntax Conventions](../../t-sql/language-elements/transact-sql-syntax-conventions-transact-sql.md)
  
## Syntax  
  
```sql
APPLOCK_TEST ( 'database_principal' , 'resource_name' , 'lock_mode' , 'lock_owner' )  
```  
  
## Arguments  
**'** *database_principal* **'**  
The user, role, or application role that can be granted permissions to objects in the database. To successfully call the function, the function caller must be a member of *database_principal*, dbo, or the db_owner fixed database role.
  
**'** *resource_name* **'**  
A lock resource name specified by the client application. The application must ensure a unique resource name. The specified name is hashed internally into a value that the [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] lock manager can internally store.  *resource_name*is **nvarchar(255)**, with no default. *resource_name* is binary compared, and is case-sensitive regardless of the collation settings of the current database.
  
**'** *lock_mode* **'**  
The lock mode to obtaine for a specific resource. *lock_mode* is **nvarchar(32)**, with no default value. *lock_mode* can have any of these values: **Shared**, **Update**, **IntentShared**, **IntentExclusive**, **Exclusive**.
  
**'** *lock_owner* **'**  
The owner of the lock, which is the *lock_owner* value when the lock was requested. *lock_owner* is **nvarchar(32)**, and the value can be either **Transaction** (the default) or **Session**. If default or **Transaction** is explicitly specified, APPLOCK_TEST must be executed from within a transaction.
  
## Return types
**smallint**
  
## Return value
0 if the lock cannot be granted to the specified owner, or 1 if the lock can be granted.
  
## Function properties
**Nondeterministic**
  
**Nonindexable**
  
**Nonparallelizable**
  
## Examples  
Two users (**User A** and **User B**), with separate sessions, run the following sequence of [!INCLUDE[tsql](../../includes/tsql-md.md)] statements.
  
**User A** runs:
  
```sql
USE AdventureWorks2012;  
GO  
BEGIN TRAN;  
DECLARE @result int;  
EXEC @result=sp_getapplock  
    @DbPrincipal='public',  
    @Resource='Form1',  
    @LockMode='Shared',  
    @LockOwner='Transaction';  
SELECT APPLOCK_MODE('public', 'Form1', 'Transaction');  
GO  
```  
  
**User B** then runs:
  
```sql
Use AdventureWorks2012;  
GO  
BEGIN TRAN;  
SELECT APPLOCK_MODE('public', 'Form1', 'Transaction');  
--Result set: NoLock  
  
SELECT APPLOCK_TEST('public', 'Form1', 'Shared', 'Transaction');  
--Result set: 1 (Lock is grantable.)  
  
SELECT APPLOCK_TEST('public', 'Form1', 'Exclusive', 'Transaction');  
--Result set: 0 (Lock is not grantable.)  
GO  
```  
  
**User A** then runs:
  
```sql
EXEC sp_releaseapplock @Resource='Form1', @DbPrincipal='public';  
GO  
```  
  
**User B** then runs:
  
```sql
SELECT APPLOCK_TEST('public', 'Form1', 'Exclusive', 'Transaction');  
--Result set: '1' (The lock is grantable.)  
GO  
```  
  
**User A** and **User B** then both run:
  
```sql
COMMIT TRAN;  
GO  
```  
  
## See also
[APPLOCK_MODE (Transact-SQL)](../../t-sql/functions/applock-mode-transact-sql.md)  
[sp_getapplock (Transact-SQL)](../../relational-databases/system-stored-procedures/sp-getapplock-transact-sql.md)  
[sp_releaseapplock (Transact-SQL)](../../relational-databases/system-stored-procedures/sp-releaseapplock-transact-sql.md)