modify post

Author: P432陳啟章

source/_posts/2024-07-14-sql-impl.md

@@ -185,6 +185,23 @@ WHERE EXISTS (SELECT 1 FROM temp_id_list t WHERE t.id = t1.id);
 DROP TABLE temp_id_list;
 ```
 
+# 更新並回傳更新後的數值
+
+產生流水號，且每當日期欄位變動，數值會從1開始
+
+```sql
+SELECT srl_no
+FROM FINAL TABLE (
+    UPDATE table1
+    SET 
+        srl_no = CASE 
+            WHEN date_var <> '1150326' THEN 1 
+            ELSE srl_no + 1 
+        END,
+        date_var = '1150326'
+);
+```
+
 # 修改結構
 
 ## 新增欄位