====== UnLock statement   ======

 
==== Description ====
 
Releases a lock set by the station in a previous Lock statement. A table or row can only be locked again (by another user, for example) after the UnLock statement has been issued.
 
==== Syntax ====
 
**UnLock**[//table_var// %%|%% All %%|%% Cursor //cursor_var//] [,//key// [,//locktype//]] Then %%|%% Else //statements//
 
==== Parameters ====
 
The UnLock statement accepts arguments for the following parameters.

^Parameter^Description^
|//table_var//|Refers to a table variable that has been locked in a previous Lock statement.|
|//cursor_var//|Contains a cursor variable. Cursor variables are initialized with a Select...By statement.|
|//key//|If a row is to be unlocked, //key// specifies which row within a table is to be unlocked. To unlock a previously locked table, pass a null in //key//.\\ \\ To UnLock all locks previously set by this workstation during the current logon session, use the UnLock All statement.|
|//locktype//|Specifies the type of unlocking that is to take place. A //locktype// can be passed as a mnemonic code (not a literal) or as a two-digit code. For details on the possible values for //locktype//, refer to the Lock statement.\\ \\ **Note:  **The code n0 is used to indicate an UnLock All.|
|Then|The statement(s) following Then are executed if the file or record is unlocked successfully.|
|Else|The statement(s) following Else are executed if the file or record cannot be unlocked. The Status() function indicates the severity of the error, and the system variable @FILE_ERROR contains details about the nature of the error.\\ ||
|Remark|Use UnLock to release each lock. Logging off the system will release all locks.|

 
==== See Also ====
 
[[lock|Lock]], [[status|Status()]]
 
==== Example ====
 
<code>
/* The following function fragment locks a record, then reads it, does some unspecified processing, and then unlocks the record, before concluding. */

Equate TRUE$  To 1
Equate FALSE$ To 0
table = "SAMPLE_CUSTOMERS"
key = 8
status = ""
Open table To tablevar Then
  Locked = FALSE$
  Loop
    Lock tablevar, key Then
      locked = TRUE$
    End Else  
      /* set up delay for network server access */
      For ctr = 1 To 1000
      Next
    End
  Until Locked Repeat
  * we're locked, now read
  Read @RECORD From tablevar,key Then
    /* do record processing here */
  End
  * now, unlock the record we've written back
  UnLock tablevar,key Else
    * error processing here
  End  ;* successfully unlocked
End Else  ;* table fails to open
  status = Set_FSError()
End  ;* table taken care of

Return status
</code>