<Sql: transaction> tag
<Sql: transaction> tag to the <sql: query> tag and <sql: update> tag to package transaction. You can be a large number of <sql: query> and <sql: update> Operations Load <sql: transaction>, making them into a single transaction.
It ensures that changes to the database instead of being submitted is to be rolled back.
Syntax
<sql:transaction dataSource="<string>" isolation="<string>"/>
Attributes
<Sql: transaction> tag has the following attributes:
| Attributes | description | If necessary | Defaults |
|---|---|---|---|
| dataSource | Used by the database (to override the default value) | no | Default database |
| isolation | Transaction isolation level (READ_COMMITTED ,, READ_UNCOMMITTED, REPEATABLE_READ or SERIALIZABLE) | no | The default database |
Examples Demo
First, you need to build in a TEST database Employees table, and then add a few records to the table, the steps are as follows:
step 1:
Open the CMD, go to the directory of the installation directory:
C:\> C:\>cd Program Files\MySQL\bin C:\Program Files\MySQL\bin>
Step 2:
Login Database:
C:\Program Files\MySQL\bin>mysql -u root -p Enter password: ******** mysql>
Step 3:
TEST establish Employees table in the database:
mysql> use TEST;
mysql> create table Students
(
id int not null,
first varchar (255),
last varchar (255),
dob date
);
Query OK, 0 rows affected (0.08 sec)
mysql>
Create a data record:
Finally, create a few records in the Employees table:
mysql> INSERT INTO Students
VALUES (100, 'Zara', 'Ali', '2002/05/16');
Query OK, 1 row affected (0.05 sec)
mysql> INSERT INTO Students
VALUES (101, 'Mahnaz', 'Fatma', '1978/11/28');
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO Students
VALUES (102, 'Zaid', 'Khan', '1980/10/10');
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO Students
VALUES (103, 'Sumit', 'Mittal', '1971/05/08');
Query OK, 1 row affected (0.00 sec)
mysql>
Now write JSP files, use the <sql: update> and <sql: transaction> to execute SQL UPDATE statements. In <sql: transaction> The code is not executed, is none Execution:
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="java.io.*,java.util.*,java.sql.*"%>
<%@ page import="javax.servlet.http.*,javax.servlet.*"%>
<%@ page import="java.util.Date,java.text.*" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/sql" prefix="sql"%>
<html>
<head>
<title>JSTL sql:transaction Tag</title>
</head>
<body>
<sql:setDataSource var="snapshot" driver="com.mysql.jdbc.Driver"
url="jdbc:mysql://localhost/TEST"
user="root" password="cohondob"/>
<%
Date DoB = new Date("2001/12/16");
int studentId = 100;
%>
<sql:transaction dataSource="${snapshot}">
<sql:update var="count">
UPDATE Students SET last = 'Ali' WHERE Id = 102
</sql:update>
<sql:update var="count">
UPDATE Students SET last = 'Shah' WHERE Id = 103
</sql:update>
<sql:update var="count">
INSERT INTO Students
VALUES (104,'Nuha', 'Ali', '2010/05/26');
</sql:update>
</sql:transaction>
<sql:query dataSource="${snapshot}" var="result">
SELECT * from Students;
</sql:query>
<table border="1" width="100%">
<tr>
<th>Emp ID</th>
<th>First Name</th>
<th>Last Name</th>
<th>DoB</th>
</tr>
<c:forEach var="row" items="${result.rows}">
<tr>
<td><c:out value="${row.id}"/></td>
<td><c:out value="${row.first}"/></td>
<td><c:out value="${row.last}"/></td>
<td><c:out value="${row.dob}"/></td>
</tr>
</c:forEach>
</table>
</body>
</html>
Results are as follows:
