SQL codes for SQL-71 issue

procedures-and-functions/stored-procedures/avg-gpa-procedure.sql

@@ -0,0 +1,20 @@
+DELIMITER //
+
+CREATE PROCEDURE CalculateAvgGPA(
+    IN dept_id INT,
+    OUT avg_gpa FLOAT
+)
+BEGIN
+    SELECT AVG(s.gpa) INTO avg_gpa
+    FROM Student s
+    JOIN Registration r ON s.id = r.student_id
+    JOIN Course c ON r.course_id = c.id
+    WHERE c.department_id = dept_id;
+END //
+
+DELIMITER ;
+
+SET @dept_id = 1;
+SET @result = 0;
+CALL CalculateAvgGPA(@dept_id, @result);
+SELECT @result AS average_gpa;

procedures-and-functions/stored-procedures/dynamic-procedure.sql

@@ -0,0 +1,15 @@
+-- DELIMITER //
+
+-- CREATE PROCEDURE DynamicCourseQuery(
+--     IN where_clause VARCHAR(1000)
+-- )
+-- BEGIN
+--     SET @sql = CONCAT('SELECT id, name, credits FROM Course WHERE ', where_clause);
+--     PREPARE stmt FROM @sql;
+--     EXECUTE stmt;
+--     DEALLOCATE PREPARE stmt;
+-- END //
+
+-- DELIMITER ;
+
+CALL DynamicCourseQuery('credits < 3 AND department_id = 1');

procedures-and-functions/stored-procedures/if-else-procedure.sql

@@ -0,0 +1,26 @@
+DELIMITER //
+
+CREATE PROCEDURE AssignLetterGrade(
+    IN numeric_grade FLOAT,
+    OUT letter_grade CHAR(2)
+)
+BEGIN
+    IF numeric_grade >= 90 THEN
+        SET letter_grade = 'A';
+    ELSEIF numeric_grade >= 80 THEN
+        SET letter_grade = 'B';
+    ELSEIF numeric_grade >= 70 THEN
+        SET letter_grade = 'C';
+    ELSEIF numeric_grade >= 60 THEN
+        SET letter_grade = 'D';
+    ELSE
+        SET letter_grade = 'F';
+    END IF;
+END //
+
+DELIMITER ;
+
+SET @input_grade = 85;
+SET @output_grade = '';
+CALL AssignLetterGrade(@input_grade, @output_grade);
+SELECT @output_grade;

procedures-and-functions/stored-procedures/inout-procedure.sql

@@ -0,0 +1,14 @@
+DELIMITER //
+
+CREATE PROCEDURE IncrementAndReturn (
+    INOUT value INT
+)
+BEGIN
+    SET value = value + 1;
+END //
+
+DELIMITER ;
+
+SET @my_value = 5;
+CALL IncrementAndReturn(@my_value);
+SELECT @my_value;