Thanks. But my remaining issue is that I may have multiple records "locked" at the same time. When I keep the name "TABLE_USER" locked, and in the meantime lock another name, for instance "TABLE_SESSION", then the previous lock "TABLE_USER" would be released right away.

One workaround is to create a create one additional database connection for each separate simultaneous lock. But that would mean I am going to have a lot of database connections to maintain.

>Hi Christian,
>
>The GET_LOCK() on MySQL is not equal to RLOCK() but - from help: "This function can be used to implement application locks or to simulate record locks. "
>
>

>* !!!this code is not tested !!!
>LOCAL lcALOCK,lcAlias
>lcALOCK=SYS(2015)
>lcAlias=SYS(2015)
>=SQLEXEC(mySQLODBCHandle,"SELECT * FROM users WHERE userName = 'Christian'",lcAlias)
>
>=SQLEXEC(mySQLODBCHandle,"SELECT IS_FREE_LOCK('TABLE_USER') AS LOCKFLAG",lcALOCK)
>IF EVAL(lcALOCK+".LOCKFLAG")=1
>   =SQLEXEC(mySQLODBCHandle,"SELECT GET_LOCK('TABLE_USER',10) AS LOCKFLAG",lcALOCK)
>
>   ** update table users
>
>*   =SQLEXEC(mySQLODBCHandle,"SELECT RELEASE_LOCK('TABLE_USER') AS LOCKFLAG",lcALOCK)
>ELSE
>   MESSAGEBOX("User already logged in")
>ENDIF
><pre>
>
>MartinaJ
>
>>Hello,
>>
>>In VFP, I used to use RLOCK("MyAlias") to lock a record, if I wanted to make sure another instance of the application would "know" that a record was being used, for instance when the appplication should display that a certain user was logged in.
>><PRE>
>>USE Users
>>LOCATE FOR userName = "Christian"
>>IF NOT RLOCK("Users")
>>    MESSAGEBOX("User already logged in")
>>ENDIF

>>
>>Now after switching to MySQL, that simple functionality got more challenging. Then I found that Get_Lock can lock any name, so I used GET_LOCK(1,"Christian") to do the same thing as above in MySQL.
>>
>>However, I found out that Get_Lock allows only one lock per database connection. Issuing a new Get_Lock unlocks the previous lock. So I would not be able to lock a user name, and additionally for instance the computer name as well.
>>
>>Anybody knows what other methods I could use in MySQL to solve that problem?