Revert "fix comments"

This reverts commit 3473888.

Author: BohuTANG

docs/en/guides/54-query/08-stored-procedure.md

@@ -6,7 +6,83 @@ A stored procedure is a set of executable commands or logic blocks stored within
 
 ## Supported Languages
 
-**Databend currently supports [SQL Scripting](/sql/sql-reference/sql-scripting) only**. Using SQL scripting, users can define procedures with control flow constructs like loops (FOR, WHILE, REPEAT) and conditionals (IF, CASE), enabling complex logic and effective multi-step operations.
+**Databend currently supports [SQL Scripting](#sql-scripting) only**. Using SQL scripting, users can define procedures with control flow constructs like loops (FOR, WHILE, REPEAT) and conditionals (IF, CASE), enabling complex logic and effective multi-step operations.
+
+### SQL Scripting
+
+In Databend, stored procedures support a rich set of features to allow users to define complex operations through SQL scripting. Here are the supported capabilities:
+
+- **Variable Declaration**: Variables can be declared using the `LET` keyword, followed by the variable name, an optional type, and the initial value.
+
+    ```sql title='Examples:'
+    LET x := 100;
+    ```
+
+- **Query Execution**: SQL queries can be executed within the script, and results can be stored in variables or result sets.
+
+    ```sql title='Examples:'
+    LET result RESULTSET := SELECT * FROM t1;
+    ```
+
+- **Control Flow Constructs**
+  - **FOR Loop**: Iterates over a range or a result set.
+
+    ```sql title='Examples:'
+    FOR i IN 1..10 DO ... END FOR;
+    ```
+
+  - **WHILE Loop**: Executes a block of code as long as a specified condition is true.
+
+    ```sql title='Examples:'
+    WHILE condition DO ... END WHILE;
+    ```
+
+  - **REPEAT Loop**: Executes a block of code until a condition is met.
+
+    ```sql title='Examples:'
+    REPEAT ... UNTIL condition END REPEAT;
+    ```
+
+  - **LOOP**: Executes a block of code indefinitely until a `BREAK` statement is encountered.
+
+    ```sql title='Examples:'
+    LOOP ... END LOOP;
+    ```
+
+  - **CASE Statement**: Allows conditional execution of code blocks based on different conditions.
+
+    ```sql title='Examples:'
+    CASE [operand]
+    WHEN condition1 THEN ...
+    WHEN condition2 THEN ...
+    ELSE ...
+    END;
+    ```
+
+  - **IF Statement**: Executes a block of code based on a condition.
+
+    ```sql title='Examples:'
+    IF condition THEN ...
+    ELSEIF condition THEN ...
+    ELSE ...
+    END IF;
+    ```
+
+- **RETURN**: Returns from the script with an optional value.
+
+    ```sql title='Examples:'
+    RETURN [expr];
+    ```
+
+- **RETURN TABLE**: Returns from the script with a table result.
+
+    ```sql title='Examples:'
+    RETURN TABLE(result_set_name | SELECT ...);
+    ```
+
+- **Comments**
+  - **Single-line comments**: `-- comment`
+  - **Multi-line comments**: `/* comment */`
 
 ## Limitations
 

docs/en/sql-reference/00-sql-reference/98-sql-scripting.md

@@ -17,9 +17,7 @@ LANGUAGE <language>
 AS $$
 BEGIN
     <procedure_body>
-    RETURN <return_value>;             -- Use to return a single value
-    -- OR
-    RETURN TABLE(<select_query>);      -- Use to return a table
+    RETURN <return_value>;
 END;
 $$;
 ```