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어떤 종류의 SQL 문을 사용하여 문을 준비할 수 있습니까?


사실, MySQL은 준비할 수 있는 다음 종류의 SQL 문만 허용하기 때문에 모든 SQL 문을 준비할 수는 없습니다.

SELECT 문

예시

mysql> PREPARE stmt FROM 'SELECT tender_value from Tender WHERE
Companyname = ?';
Query OK, 0 rows affected (0.09 sec)
Statement prepared

mysql> SET @A = 'Singla Group.';
Query OK, 0 rows affected (0.00 sec)

mysql> EXECUTE stmt using @A;
+--------------+
| tender_value |
+--------------+
|   220.255997 |
+--------------+
1 row in set (0.07 sec)

mysql> DEALLOCATE PREPARE stmt;
Query OK, 0 rows affected (0.00 sec)

삽입, 교체, 업데이트 및 삭제

데이터를 수정하는 명령문.

예시

mysql> PREPARE stmt1 FROM 'DELETE from Tender WHERE Sr = ?';
Query OK, 0 rows affected (0.00 sec)
Statement prepared

mysql> SET @A = 4;
Query OK, 0 rows affected (0.00 sec)

mysql> EXECUTE stmt1;
ERROR 1210 (HY000): Unknown error 1210

mysql> EXECUTE stmt1 using @A;
Query OK, 1 row affected (0.08 sec)

mysql> DEALLOCATE PREPARE stmt1;
Query OK, 0 rows affected (0.00 sec)

mysql> Select * from tender;
+----+---------------+--------------+
| Sr | CompanyName   | Tender_value |
+----+---------------+--------------+
| 1  | Abc Corp.     |   250.369003 |
| 2  | Khaitan Corp. |   265.588989 |
| 3  | Singla group. |   220.255997 |
+----+---------------+--------------+
3 rows in set (0.00 sec)

CREATE TABLE 문.

예시

mysql> PREPARE stmt3 FROM 'CREATE TABLE Student(Id INT, Name
Varchar(20))';
Query OK, 0 rows affected (0.00 sec)
Statement prepared

mysql> EXECUTE stmt3;
Query OK, 0 rows affected (0.73 sec)

mysql> DEALLOCATE PREPARE stmt3;
Query OK, 0 rows affected (0.00 sec)

SET, DO 및 많은 SHOW 문

예시

mysql> PREPARE stmt10 FROM 'SHOW TABLES';
Query OK, 0 rows affected (0.00 sec)
Statement prepared

mysql> EXECUTE stmt10;
+-------------------+
| Tables_in_query   |
+-------------------+
| emp               |
| emp123            |
| emp_t             |
| examination_btech |
| new_number        |
| student           |
| student_detail    |
| student_info      |
| tender            |
| website           |
+-------------------+
10 rows in set (0.00 sec)