MySQL :: MySQL 8.0 Reference Manual :: 15.6.7 Condition Handling (original) (raw)
15.6.7 Condition Handling
Conditions may arise during stored program execution that require special handling, such as exiting the current program block or continuing execution. Handlers can be defined for general conditions such as warnings or exceptions, or for specific conditions such as a particular error code. Specific conditions can be assigned names and referred to that way in handlers.
To name a condition, use theDECLARE ... CONDITION statement. To declare a handler, use theDECLARE ... HANDLER statement. SeeSection 15.6.7.1, “DECLARE ... CONDITION Statement”, andSection 15.6.7.2, “DECLARE ... HANDLER Statement”. For information about how the server chooses handlers when a condition occurs, seeSection 15.6.7.6, “Scope Rules for Handlers”.
To raise a condition, use theSIGNAL statement. To modify condition information within a condition handler, useRESIGNAL. SeeSection 15.6.7.1, “DECLARE ... CONDITION Statement”, andSection 15.6.7.2, “DECLARE ... HANDLER Statement”.
To retrieve information from the diagnostics area, use theGET DIAGNOSTICS statement (seeSection 15.6.7.3, “GET DIAGNOSTICS Statement”). For information about the diagnostics area, see Section 15.6.7.7, “The MySQL Diagnostics Area”.