Unable to query information_schema.referential_constraints for DELETE_RULE column without qualifying column name

[mcronce]

Overview of the Issue

The haskell/persistent-mysql test fails trying to execute the following query (formatted for readability):

SELECT
    KCU.REFERENCED_TABLE_NAME,
    KCU.CONSTRAINT_NAME,
    KCU.ORDINAL_POSITION,
    DELETE_RULE,
    UPDATE_RULE
FROM
    INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS KCU 
    INNER JOIN INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS AS RC ON
        KCU.CONSTRAINT_NAME = RC.CONSTRAINT_NAME
WHERE
    KCU.TABLE_SCHEMA = 'test' AND 
    KCU.TABLE_NAME = 'data_type_table' AND 
    KCU.COLUMN_NAME = 'id' AND 
    KCU.REFERENCED_TABLE_SCHEMA = 'test'
    AND KCU.CONSTRAINT_NAME = 'data_type_table_id_fkey'
ORDER BY KCU.CONSTRAINT_NAME, KCU.COLUMN_NAME;

What's interesting is that if I DESCRIBE information_schema.referential_constraints, it reports that the column is there. Additionally, if I add table qualifiers to those two columns, it works:

SELECT
    KCU.REFERENCED_TABLE_NAME,
    KCU.CONSTRAINT_NAME,
    KCU.ORDINAL_POSITION,
    RC.DELETE_RULE,
    RC.UPDATE_RULE
FROM
    INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS KCU
    INNER JOIN INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS AS RC ON
        KCU.CONSTRAINT_NAME = RC.CONSTRAINT_NAME
WHERE
    KCU.TABLE_SCHEMA = 'test' AND
    KCU.TABLE_NAME = 'data_type_table' AND
    KCU.COLUMN_NAME = 'id' AND
    KCU.REFERENCED_TABLE_SCHEMA = 'test'
    AND KCU.CONSTRAINT_NAME = 'data_type_table_id_fkey'
ORDER BY KCU.CONSTRAINT_NAME, KCU.COLUMN_NAME;
Empty set (0.01 sec)

Reproduction Steps

Pasting the following query into a mysql CLI prompt will reproduce the issue:

SELECT DELETE_RULE, UPDATE_RULE FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS KCU INNER JOIN INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS AS RC ON  KCU.CONSTRAINT_NAME = RC.CONSTRAINT_NAME WHERE KCU.TABLE_SCHEMA = 'test' AND KCU.TABLE_NAME = 'data_type_table' AND KCU.COLUMN_NAME = 'id' AND KCU.REFERENCED_TABLE_SCHEMA = 'test' AND KCU.CONSTRAINT_NAME = 'data_type_table_id_fkey' ORDER BY KCU.CONSTRAINT_NAME, KCU.COLUMN_NAME;

Binary version

Using vttestserver, but from vtcombo in the same container:

$ /vt/bin/vtcombo -version
ERROR: logging before flag.Parse: E0122 18:55:31.686379    2285 syslogger.go:149] can't connect to syslog
Version: e259a08f0 (Git branch 'master') built on Fri Jan 22 04:19:58 UTC 2021 by vitess@b581768d34fd using go1.15.6 linux/amd64

Operating system and Environment details

Inside the vttestserver container:

PRETTY_NAME="Debian GNU/Linux 10 (buster)"
NAME="Debian GNU/Linux"
VERSION_ID="10"
VERSION="10 (buster)"
VERSION_CODENAME=buster
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"
vitess@3e5d5c6a960a:/$ uname -sr 
Linux 5.10.2-2-MANJARO
vitess@3e5d5c6a960a:/$ uname -m
x86_64

Log Fragments

E0122 19:45:25.903237     706 vtgate.go:440] Execute: symbol DELETE_RULE not found, request: map[BindVariables:map[vtg1:type:VARBINARY value:"test"  vtg2:type:VARBINARY value:"data_type_table"  vtg3:type:VARBINARY value:"id"  vtg4:type:VARBINARY value:"data_type_table_id_fkey" ] Session:autocommit:true target_string:"test" options:<included_fields:ALL > found_rows:1 row_count:-1 DDLStrategy:"direct" SessionUUID:"570c9022-5cea-11eb-a676-0242ac110003" enable_system_settings:true Sql:SELECT DELETE_RULE,     UPDATE_RULE FROM     INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS KCU      INNER JOIN INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS AS RC ON         KCU.CONSTRAINT_NAME = RC.CONSTRAINT_NAME WHERE     KCU.TABLE_SCHEMA = 'test' AND      KCU.TABLE_NAME = 'data_type_table' AND      KCU.COLUMN_NAME = 'id' AND      KCU.REFERENCED_TABLE_SCHEMA = 'test'     AND KCU.CONSTRAINT_NAME = 'data_type_table_id_fkey' ORDER BY KCU.CONSTRAINT_NAME, KCU.COLUMN_NAME]