ALTER TABLE pulse_attempt_evidence
 DROP CHECK ck_attempt_evidence_outcome,
 MODIFY COLUMN outcome VARCHAR(16) NOT NULL COMMENT 'Worker 声明的结果：SUCCEEDED、FAILED、UNKNOWN 或已确认停止且本次无遗留效果的 CANCELLED',
 ADD CONSTRAINT ck_attempt_evidence_outcome CHECK(outcome IN ('SUCCEEDED','FAILED','UNKNOWN','CANCELLED'));