251117:1700 first commit

docs/SQL/triggers.sql

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+-- trigger
+DROP TRIGGER IF EXISTS trg_rfa_revisions_is_current;
+DROP TRIGGER IF EXISTS trg_rfa_revisions_is_current_upd;
+DROP TRIGGER IF EXISTS trg_rfa_revisions_auto_reset;
+-- ============================================================
+-- ⚙️ TRIGGERS
+-- ============================================================
+-- ป้องกันไม่ให้มี revision ที่ is_current=TRUE ซ้ำใน rfa_id เดียวกัน
+DELIMITER $$
+CREATE TRIGGER trg_rfa_revisions_is_current
+BEFORE INSERT ON rfa_revisions
+FOR EACH ROW
+BEGIN
+  IF NEW.is_current = TRUE THEN
+    IF (SELECT COUNT(*) FROM rfa_revisions WHERE rfa_id = NEW.rfa_id AND is_current = TRUE) > 0 THEN
+      SIGNAL SQLSTATE '45000'
+        SET MESSAGE_TEXT = 'Cannot insert more than one current revision per RFA.';
+    END IF;
+  END IF;
+END$$
+DELIMITER ;
+DELIMITER $$
+CREATE TRIGGER trg_rfa_revisions_is_current_upd
+BEFORE UPDATE ON rfa_revisions
+FOR EACH ROW
+BEGIN
+  IF NEW.is_current = TRUE AND (OLD.is_current IS NULL OR OLD.is_current = FALSE) THEN
+    IF (SELECT COUNT(*) FROM rfa_revisions WHERE rfa_id = NEW.rfa_id AND is_current = TRUE AND correspondences_id <> OLD.correspondences_id) > 0 THEN
+      SIGNAL SQLSTATE '45000'
+        SET MESSAGE_TEXT = 'Cannot set more than one current revision per RFA.';
+    END IF;
+  END IF;
+END$$
+DELIMITER ;
+-- ทำให้เวลาสร้าง revision ใหม่ที่ is_current=TRUE ระบบจะ set revision เดิมเป็น FALSE อัตโนมัติ
+DELIMITER $$
+CREATE TRIGGER trg_rfa_revisions_auto_reset
+BEFORE INSERT ON rfa_revisions
+FOR EACH ROW
+BEGIN
+  IF NEW.is_current = TRUE THEN
+    UPDATE rfa_revisions
+      SET is_current = FALSE
+      WHERE rfa_id = NEW.rfa_id;
+  END IF;
+END$$
+DELIMITER ;