Database Related

Difference Between Prepared Statements And Parameterized Queries

Both prepared statements and parameterized queries are exactly the same thing. Basically, the word ‘prepared statement’ is most frequently used; however, there is no difference between these two terms.

Prepared statements and parameterized queries are database management system’s characteristics that actually act as templates in which the execution of SQL occurs. The parameters are the actual values that pass through into the SQL. This is why all these templates are known as parameterized queries. Moreover, the SQL within the template is also optimized, parsed and compiled before the SQL is sent off for the execution– in other words “prepared”. Therefore, all these templates are generally also known as prepared statements. Thus, always remember that prepared statements and parameterized queries are the two names given to the same thing.

Benefits Of Using Prepared Statements

The 2 main advantages provided by the prepared statements are as follows.

First of all, they provide efficient performance. Although, the execution of a prepared statement can happen several times, it is optimized and compiled just once using the database engine.

Due to the fact that a prepared statement does not need to be optimized and compiled each and every time there is a change in the values of the query, it offers a definite performance advantage. However, remember that when a prepared statement is compiled, all the query optimization cannot occur.

This reason behind this is that the best query plan may also rely on the certain values of the parameters being passed in. Overtime, the best query plan may also change due to the fact that the indices and database tables also change with time.

How SQL Is “Prepared”?

  • The creation of prepared SQL requires calling the respective prepare procedure in each language.
  • After this, the prepared SQL template is forwarded to the DBMS (it can be DB2, MySQL or whatever) having “?”(The placeholder values) left blank.
  • Now, the DBMS will perform, parse and compile query optimization on the template.
  • After this, the DBMS will store the result; however, it cannot execute the result as it does not have any values for the execution as there is no data in the parameters/placeholders.
  • Once the data is passed in for the parameters and respective execute function is called, the SQL is executed.

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