111 lines
4.0 KiB
PL/PgSQL
111 lines
4.0 KiB
PL/PgSQL
-- +migrate Up
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-- 添加照片表的外键约束
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ALTER TABLE photos
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ADD CONSTRAINT fk_photos_album_id
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FOREIGN KEY (album_id) REFERENCES albums(id) ON DELETE SET NULL;
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ALTER TABLE photos
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ADD CONSTRAINT fk_photos_category_id
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FOREIGN KEY (category_id) REFERENCES categories(id) ON DELETE SET NULL;
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-- 添加相册表的外键约束（如果还没有的话）
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-- 这些约束在创建相册表时可能已经存在，这里做一个保险
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-- 添加一些有用的触发器和函数
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-- 创建照片计数更新触发器（用于相册和分类）
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CREATE OR REPLACE FUNCTION update_photo_counts()
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RETURNS TRIGGER AS $$
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BEGIN
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IF TG_OP = 'INSERT' THEN
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-- 更新相册照片数量
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IF NEW.album_id IS NOT NULL THEN
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UPDATE albums SET photo_count = photo_count + 1 WHERE id = NEW.album_id;
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END IF;
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-- 更新分类照片数量
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IF NEW.category_id IS NOT NULL THEN
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UPDATE categories SET photo_count = photo_count + 1 WHERE id = NEW.category_id;
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END IF;
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RETURN NEW;
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ELSIF TG_OP = 'DELETE' THEN
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-- 更新相册照片数量
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IF OLD.album_id IS NOT NULL THEN
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UPDATE albums SET photo_count = photo_count - 1 WHERE id = OLD.album_id;
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END IF;
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-- 更新分类照片数量
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IF OLD.category_id IS NOT NULL THEN
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UPDATE categories SET photo_count = photo_count - 1 WHERE id = OLD.category_id;
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END IF;
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RETURN OLD;
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ELSIF TG_OP = 'UPDATE' THEN
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-- 处理相册变更
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IF OLD.album_id IS DISTINCT FROM NEW.album_id THEN
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IF OLD.album_id IS NOT NULL THEN
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UPDATE albums SET photo_count = photo_count - 1 WHERE id = OLD.album_id;
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END IF;
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IF NEW.album_id IS NOT NULL THEN
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UPDATE albums SET photo_count = photo_count + 1 WHERE id = NEW.album_id;
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END IF;
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END IF;
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-- 处理分类变更
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IF OLD.category_id IS DISTINCT FROM NEW.category_id THEN
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IF OLD.category_id IS NOT NULL THEN
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UPDATE categories SET photo_count = photo_count - 1 WHERE id = OLD.category_id;
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END IF;
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IF NEW.category_id IS NOT NULL THEN
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UPDATE categories SET photo_count = photo_count + 1 WHERE id = NEW.category_id;
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END IF;
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END IF;
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RETURN NEW;
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END IF;
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RETURN NULL;
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END;
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$$ language 'plpgsql';
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-- 创建触发器
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CREATE TRIGGER trigger_update_photo_counts
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AFTER INSERT OR UPDATE OR DELETE ON photos
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FOR EACH ROW EXECUTE FUNCTION update_photo_counts();
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-- 创建相册计数更新触发器（用于分类）
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CREATE OR REPLACE FUNCTION update_album_counts()
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RETURNS TRIGGER AS $$
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BEGIN
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IF TG_OP = 'INSERT' THEN
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IF NEW.category_id IS NOT NULL THEN
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UPDATE categories SET album_count = album_count + 1 WHERE id = NEW.category_id;
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END IF;
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RETURN NEW;
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ELSIF TG_OP = 'DELETE' THEN
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IF OLD.category_id IS NOT NULL THEN
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UPDATE categories SET album_count = album_count - 1 WHERE id = OLD.category_id;
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END IF;
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RETURN OLD;
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ELSIF TG_OP = 'UPDATE' THEN
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IF OLD.category_id IS DISTINCT FROM NEW.category_id THEN
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IF OLD.category_id IS NOT NULL THEN
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UPDATE categories SET album_count = album_count - 1 WHERE id = OLD.category_id;
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END IF;
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IF NEW.category_id IS NOT NULL THEN
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UPDATE categories SET album_count = album_count + 1 WHERE id = NEW.category_id;
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END IF;
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END IF;
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RETURN NEW;
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END IF;
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RETURN NULL;
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END;
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$$ language 'plpgsql';
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CREATE TRIGGER trigger_update_album_counts
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AFTER INSERT OR UPDATE OR DELETE ON albums
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FOR EACH ROW EXECUTE FUNCTION update_album_counts();
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-- +migrate Down
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DROP TRIGGER IF EXISTS trigger_update_album_counts ON albums;
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DROP FUNCTION IF EXISTS update_album_counts();
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DROP TRIGGER IF EXISTS trigger_update_photo_counts ON photos;
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DROP FUNCTION IF EXISTS update_photo_counts();
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ALTER TABLE photos DROP CONSTRAINT IF EXISTS fk_photos_category_id;
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ALTER TABLE photos DROP CONSTRAINT IF EXISTS fk_photos_album_id; |