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10 lines
473 B
10 lines
473 B
-- 第1 步：先加字段，允许 NULL，不设默认值
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ALTER TABLE enforcement_registration
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ADD COLUMN update_time DATETIME NULL;
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-- 第 2 步：用 create_time 填充已有行
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UPDATE enforcement_registration SET update_time = create_time WHERE update_time IS NULL;
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-- 第 3 步：改为自动更新（加上 DEFAULT + ON UPDATE）
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ALTER TABLE enforcement_registration
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MODIFY COLUMN update_time DATETIME DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP;
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