The difference between mysql stored procedures and functions

The difference between stored procedures and functions: Stored procedures can return multiple values ​​or result sets, while functions only return a single scalar value. Stored procedures are typically executed within a transaction, whereas functions can be executed independently. Stored procedures have side effects, whereas functions usually don't. Stored procedures are reusable, but functions are generally easier to reuse than stored procedures. Stored procedures generally perform better, but functions may be faster if only simple calculations are performed.

The difference between stored procedures and functions

Definition:

• Stored procedure: A set of precompiled SQL statements used to perform complex operations. It can receive input parameters and return output parameters or a result set.
• Function: A special type of stored procedure that only returns a scalar value (a single data value).

Main differences:

1. Return value:

• The stored procedure can return multiple A value (via an output parameter) or a result set.
• Function can only return a single scalar value.

2. Transaction control:

• Stored procedures are usually executed within a transaction, which means that either all statements are executed successfully, or the entire transaction rollback.
• Functions that can be executed without using transactions are called non-deterministic functions.

3. Side effects:

• Stored procedures usually have side effects, such as updating or inserting data.
• Functions usually have no side effects and only return a value.

4. Reusability:

• Both stored procedures and functions can be reused in multiple queries.
• However, functions are generally easier to reuse than stored procedures because they only return a value.

5. Performance:

• Stored procedures usually perform better than functions because they are precompiled.
• However, if the function only performs simple calculations, it may be faster than a stored procedure.

Selection criteria:

• If you need to perform complex operations, have side effects and need to return multiple values, use stored procedures.
• Use a function if you only need to return a single scalar value and have no side effects.

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