Initial commit

migrations/triggers_hospital_admission.sql

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+-- Общая функция возвращения всех госпитализаций и периодов пациента
+CREATE OR REPLACE FUNCTION get_hospitalization_periods (p_patient_id int)
+    RETURNS TABLE (
+        admission_datetime timestamp,
+        discharge_datetime timestamp
+    )
+    AS $$
+BEGIN
+    RETURN QUERY
+    SELECT
+        ha.admission_datetime,
+        hd.discharge_datetime
+    FROM
+        hospital_admission ha
+    LEFT JOIN hospital_discharge hd ON ha.hospital_admission_id = hd.hospital_admission_id
+WHERE
+    ha.patient_id = p_patient_id;
+END;
+$$
+LANGUAGE plpgsql;
+
+-- Триггер: запрещает новую госпитализацию при наличии незавершённой
+CREATE OR REPLACE FUNCTION check_active_hospitalization ()
+    RETURNS TRIGGER
+    AS $$
+DECLARE
+    open_hospitalization boolean;
+BEGIN
+    SELECT
+        EXISTS (
+            SELECT
+                1
+            FROM
+                get_hospitalization_periods (NEW.patient_id)
+            WHERE
+                discharge_datetime IS NULL) INTO open_hospitalization;
+    IF open_hospitalization THEN
+        RAISE EXCEPTION
+            USING ERRCODE = 'P0001', MESSAGE = '10001: ACTIVE_HOSPITALIZATION_EXISTS';
+        END IF;
+        RETURN NEW;
+END;
+$$
+LANGUAGE plpgsql;
+
+-- Триггер: запрещает перекрытие госпитализаций
+CREATE OR REPLACE FUNCTION check_hospitalization_overlap ()
+    RETURNS TRIGGER
+    AS $$
+DECLARE
+    overlap_found boolean;
+BEGIN
+    SELECT
+        EXISTS (
+            SELECT
+                1
+            FROM
+                get_hospitalization_periods (NEW.patient_id)
+            WHERE
+                discharge_datetime IS NOT NULL
+                AND NEW.admission_datetime < discharge_datetime
+                AND NEW.admission_datetime > admission_datetime) INTO overlap_found;
+    IF overlap_found THEN
+        RAISE EXCEPTION
+            USING ERRCODE = 'P0001', MESSAGE = '10002: HOSPITALIZATION_OVERLAP';
+        END IF;
+        RETURN NEW;
+END;
+$$
+LANGUAGE plpgsql;
+
+-- Подключение триггеров на hospital_admissions
+CREATE TRIGGER trg_check_active_hospitalization
+    BEFORE INSERT ON hospital_admission
+    FOR EACH ROW
+    EXECUTE FUNCTION check_active_hospitalization ();
+
+CREATE TRIGGER trg_check_hospitalization_overlap
+    BEFORE INSERT ON hospital_admission
+    FOR EACH ROW
+    EXECUTE FUNCTION check_hospitalization_overlap ();
+