Qus: What is start transaction commit & roll back transaction & how to use them? wht do you mean by roll back transaction?
START TRANSACTION or BEGIN start a new transaction.
COMMIT - commits the current transaction, making its changes permanent.
ROLLBACK - rolls back the current transaction, canceling its changes.
Difference between custom SQL & dynamic sql ? Allino
In Custom SQL, you can pass inputs to your SQL query at runtime. With DynamicSQL, you can pass your entire SQL statement, or part of your SQL statement can be passed at runtime; along with inputs to it. So basically you can build your SQL dynamically at runtime.
• You use Custom SQL when SQL query is fixed with input variable that are passed to the custom adapter service. You use dynamic SQL, if SQL query changes during the runtime; in this cases you prepare the sql query and pass it to dynamic adapter service in the runtime.
• Custom SQL and Dynamic SQL we have to write the queries explicitly. The main difference between Custom SQL and Dynamic SQL is; in Custom SQL we can give the input values at design time. In Dynamic SQL we can give the input values at run time.
• Custom SQL is faster than the Dynamic SQL because Custom SQL is pre-compiled (at design time) but dynamic SQL is not pre-compiled (compiled at runtime).
• Dynamic SQL is more versatile than the Custom SQL.