The <sql:update> tag executes the provided SQL query through its body or through its sql attribute. Execution SQL queries using <sql:update> tag does not return any data. This tag can execute INSERT, UPDATE and DELETE statements.
Syntax-
<sql:update var=”<string>” scope=”<string>” sql=”<string>” dataSource=”<string>”/>
JSTL <sql:Update> Tag has following attributes.
1. datasource Attribute: Specifies the datasource. Make sure that you already created datasource using serDataSource tag before writing query.
2. sql Attribute: Specifies the SQL statement to run on database.
3. var Attribute: Store the result of SQL statement.
JSTL SQL UPDATE Tag Example:
Now let us write a JSP which will make use of <sql:update> to execute a SQL INSERT statement to create one record in the table as follows:
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="sql" uri="http://java.sun.com/jsp/jstl/sql"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>JSTL SQL Tags - setDataSource Example</title>
</head>
<body>
<sql:setDataSource driver="com.mysql.jdbc.Driver"
url="jdbc:mysql://localhost:3306/database_name"
var="localSource"
user="database_user"
password="database_password"/>
<sql:update dataSource="${snapshot}" var="count">
INSERT INTO Employees VALUES (333, 27, 'Anamika', 'Rajput');
</sql:update>
<sql:query dataSource="${localSource}" var="result">
SELECT * from Employees;
</sql:query>
<table border="1" width="100%">
<tr>
<th>Emp ID</th>
<th>First Name</th>
<th>Last Name</th>
<th>Age</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.age}"/></td>
</tr>
</c:forEach>
</table>
</body>
</html>
Now try to access above JSP, which should display the following result:
| Emp ID | First Name | Last Name | Age |
|---|---|---|---|
| 1111 | Dinesh | Rajput | 27 |
| 2222 | Sweety | Rajput | 23 |
| 3333 | Anamika | Rajput | 23 |
