DIfference Between Stored Procedures and Prepared Statements?

What is the 开发者_如何学运维difference between Stored Procedures and Prepared Statements... And which one is better and why...!! I was trying to google it but haven't got any better article...

Stored procedures are a sequence of instructions in PL/SQL language. Is a programming language implemented by some DBMS, that lets you store sequences of queries frequently applied to your model, and share the processing load with the application layer.

Prepared statements are queries written with placeholders instead of actual values. You write the query and it is compiled just once by the DBMS, and then you just pass values to place into the placeholders. The advantage of using prepared statements is that you enhance the performance considerably, and protect your applications from SQL Injection.

The difference is you cant store prepared statements. You must "prepare" them every time you need to execute one. Stored procedures, on the other hand, can be stored, associated to a schema, but you need to know PL/SQL to write them.

You must check if your DBMS supports them.

Both are very usefull tools, you might want to combine.

Hope this short explanation to be useful to you!

The other answers have hinted at this, but I'd like to list the Pros and Cons explicitly:

Stored Procedures

PROS:

1. Each query is processed more rapidly than a straight query, because the server pre-compiles them.
2. Each query need only be written once. It can be executed as many times as needed, even across different sessions and different connections.
3. Allows queries to include programming constructs (such as loops, conditional statements, and error handling) that are either impossible or difficult to write in SQL alone.

CONS

1. Require knowledge of whatever programming language the database server uses.
2. Can sometimes require special permissions to write them or call them.

Prepared Statements

PROS

1. Like stored routines, are quick because queries are pre-compiled.

CONS

1. Need to be re-compiled with each connection or session.
2. To be worth the overhead, each prepared statement must be executed more than once (such as in a loop). If a query is executed only once, more overhead goes into preparation of the prepared statement than you get back since the server needs to compile the SQL anyway, but also make the prepared statement.

For my money, I'd go with Stored Procedures every time since they only need to be written and compiled once. After that, every call to the procedure leads to saved time, whether you're on a new connection or not, and whether you're calling the procedure in a loop or not. The only downside is needing to spend some time learning the programming language. If I didn't have permissions to write stored procedures, I would use a prepared statement, but only if I had to repeatedly make the same query multiple times in the same session.

This is the conclusion I've come to after several months of off-and-on research into the differences between these two constructs. If anyone is able to correct bad generalizations I'm making, it will be worth any loss to reputation.

A stored Procedure is stored in the DB - depending on which DB (Oracle, MS SQL Server etc.) it is compiled and potentially prepared optimized when you create it on the server...

A prepared statement is a statement which is parsed by the server and an execution plan is created by the server ready for execution whenever you run the statement... usually it makes sense when a statement is run more than once... depending on the DB server (Oracle etc.) and even sometimes configuration options these "preparation" are either session-specific or "global"...

There is no "better" when you compare these two since they have their specific use cases...