MySQL Bugs: #94366: show errors from previous MySQL operation

Bug #94366	show errors from previous MySQL operation
Submitted:	16 Feb 2019 20:22	Modified:	17 Feb 2019 17:00
Reporter:	PRABHU R	Email Updates:
Status:	Not a Bug	Impact on me:	None
Category:	MySQL Server: DML	Severity:	S3 (Non-critical)
Version:	8.0	OS:	Windows
Assigned to:		CPU Architecture:	Other
Tags:	Errors Messages

Description:
I did,
       SELECT * FROM unknown_table;
       SELECT @@error_count;

       --Returns Error
       --Returns Errorcount as 1
       
       SELECT 1;
       SELECT @@error_count;

       --Returns 1
       --Returns Errorcount as 1

I expected,

       SELECT * FROM unknown_table;
       SELECT @@error_count;

       --Returns Error
       --Returns Errorcount as 1

       SELECT 1;
       SELECT @@error_count;

       --Returns 1
       --Returns Errorcount as 0

It happens,

           show errors from previous MySQL operation

How to repeat:
I did,
       SELECT * FROM unknown_table;
       SELECT @@error_count;

       --Returns Error
       --Returns Errorcount as 1
       
       SELECT 1;
       SELECT @@error_count;

       --Returns 1
       --Returns Errorcount as 1

I expected,

       SELECT * FROM unknown_table;
       SELECT @@error_count;

       --Returns Error
       --Returns Errorcount as 1

       SELECT 1;
       SELECT @@error_count;

       --Returns 1
       --Returns Errorcount as 0

It happens,

           show errors from previous MySQL operation

Thank you for the bug report. Behavior according documented on Manual:
https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html

error_count

The number of errors that resulted from the last statement that generated messages. This variable is read only. See Section 13.7.6.17, “SHOW ERRORS Syntax”. 

Your example the last statement with generated messages continues to be:
SELECT * FROM unknown_table; and SELECT 1; doesn't generates error message,

Bug #94368 marked as duplicate of this one