add options for while

data/3.MySQL高阶/3.过程化编程/4.WHILE/while.md

@@ -27,7 +27,7 @@ end LOOP trace;
 ## 答案
 
 ```sql
-trade: WHILE @total_price > 20000 DO
+trade: WHILE @total_price <= 20000 DO
     -- 省略交易过程
 END WHILE trade;
 ```
@@ -65,3 +65,27 @@ trade: WHILE @total_price > 20000
     -- 省略交易过程
 END WHILE;
 ```
+
+### E
+
+```sql
+trade: WHILE @total_price < 20000
+    -- 省略交易过程
+END WHILE trade;
+```
+
+### F
+
+```sql
+trade: WHILE @total_price <= 20000 DO
+    -- 省略交易过程
+END WHILE trade;
+```
+
+### G
+
+```sql
+WHILE @total_price > 20000
+    -- 省略交易过程
+END WHILE;
+```
\ No newline at end of file