phpMyAdmin 存储过程说明

Question

I have found the following option screen when creating a Stored Procedure in phpMyAdmin.

Now I wonder what everything means.

I know the Routine name , Type , Parameters , Definition , Definer , Security type and Comment options.

I however do not know what to do with Is deterministic and SQL data access . I have tried to Google it, but couldn't find it. Can someone enlighten me what those values mean?

Answer 1

IS DETERMINISTIC:

A procedure or function is considered “deterministic” if it always produces the same result for the same input parameters, and “not deterministic” otherwise. If neither DETERMINISTIC nor NOT DETERMINISTIC is given in the routine definition, the default is NOT DETERMINISTIC.

SQL DATA ACCESS:

• CONTAINS SQL indicates that the routine does not contain statements that read or write data. This is the default if none of these characteristics is given explicitly. Examples of such statements are SET @x = 1 or DO RELEASE_LOCK('abc'), which execute but neither read nor write data.

• NO SQL indicates that the routine contains no SQL statements.

• READS SQL DATA indicates that the routine contains statements that read data (for example, SELECT), but not statements that write data.

• MODIFIES SQL DATA indicates that the routine contains statements that may write data (for example, INSERT or DELETE).