In MySQL, you cannot do this: create table t (i int primary key, j int); insert into t values (1, 1); update t set j = (select max(j) from t) + 1; The UPDATE statement will raise an error as follows: SQL Error [1093] [HY000]: You can't specify target table 't' for update in FROM … Continue reading Workaround for MySQL’s “can’t specify target table for update in FROM clause” Error
Tag: FOR UPDATE
FOR UPDATE simulation in SQL Server and CUBRID
Pessimistic locking is useful every now and then when you explicitly want to lock a given set of rows for a subsequent UPDATE, or for database-based inter-process synchronisation and locking. Normally, you would use the SQL Standard FOR UPDATE clause, which is supported in most databases. A SQL standard example -- This statement will produce … Continue reading FOR UPDATE simulation in SQL Server and CUBRID