error code for sysvar.go (#634)

Author: cfzjywxk

mysql/errcode.go

@@ -972,6 +972,8 @@ const (
 	ErrIndexStateCantNone         = 8044
 	ErrInvalidRecordKey           = 8045
 	ErrColumnStateCantNone        = 8046
+	ErrUnsupportedValueForVar     = 8047
+	ErrUnsupportedIsolationLevel  = 8048
 
 	// TiKV/PD errors.
 	ErrPDServerTimeout    = 9001

mysql/errname.go

@@ -968,6 +968,8 @@ var MySQLErrName = map[uint16]string{
 	ErrColumnStateNonPublic:       "can not use non-public column",
 	ErrIndexStateCantNone:         "index %s can't be in none state",
 	ErrInvalidRecordKey:           "invalid record key",
+	ErrUnsupportedValueForVar:     "variable '%s' does not yet support value: %s",
+	ErrUnsupportedIsolationLevel:  "The isolation level '%s' is not supported. Set tidb_skip_isolation_level_check=1 to skip this error",
 
 	// TiKV/PD errors.
 	ErrPDServerTimeout:    "PD server timeout",