Prepared statements
In SQL, prepared statements are used to templatize similar queries or updates. ÃÛ¶¹ÊÓƵ Experience Platform Query Service supports prepared statements by using a parameterized query. This can optimize performance, as you no longer need to repetitiously re-parse a query.
Using prepared statements
When using prepared statements, the following syntaxes are supported:
Prepare a prepared statement prepare
This SQL query saves the written SELECT query with the name given as PLAN_NAME. You can use variables, such as $1 in lieu of actual values. This prepared statement will be saved during the current session. Please note that plan names are not case sensitive.
SQL format
PREPARE {PLAN_NAME} AS {SELECT_QUERY}
Sample SQL
PREPARE test AS SELECT * FROM table WHERE country = $1 AND city = $2;
Execute a prepared statement execute
This SQL query uses the prepared statement which was created earlier.
SQL format
EXECUTE {PLAN_NAME}('{PARAMETERS}')
Sample SQL
EXECUTE test('canada', 'vancouver');
Deallocate a prepared statement deallocate
This SQL query is used to delete the named prepared statement.
SQL format
DEALLOCATE {PLAN_NAME}
Sample SQL
DEALLOCATE test;
Example flow using prepared statements
Initially, you can have an SQL query, such as the one below:
SELECT * FROM table WHERE id >= 10000 AND id <= 10005;
The SQL query above will return the following response:
This SQL query can be parameterized by using the following prepared statement:
PREPARE getIdRange AS SELECT * FROM table WHERE id >= $1 AND id <= $2;
Now, the prepared statement can be executed by using the following call:
EXECUTE getIdRange(10000, 10005);
When this is called, you will see the exact same results as before:
After you have finished using the prepared statement, you can deallocate it by using the following call:
DEALLOCATE getIdRange;