What kind of SQL statements can be used to prepare statements?
In fact, it is impossible to prepare all SQL statements, because MySQL only allows the preparation of the following types of SQL statements:
SELECT statement
Example
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)
INSERT, REPLACE, UPDATE and DELETE
Statements that modify data.
Example
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 statement.
Example
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 and many SHOW statements
Example
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)
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