Dinesh on Java

Categories: JSTL

JSTL SQL Param<sql:param> Tag Example

JSTL Param Tag provides the value of the parameter. In SQL update statement, paramters are sent using JSTL Param tag. The <sql:param> tag is used to set the parameters to the SQL query. We use this tag to set the placeholders and data to match the placeholder position to insert the data into the database or to update the database records. This tag is used as a nested tag inside the <sql:query> to provide the parameters to the query.

Syntax
<sql:param value=”<string>”/>

JSTL Param Tag has following attribute.

1. value Attribute: Specifies the value of the parameter.

JSTL <sql:param> Tag Example:-
The following example takes input from the employee and inserts the entered citizen information into the database using the combination of <sql:query> and <sql:param> tags. The list of records are displayed in tabular manner once the new record has been inserted.

Now let us write a JSP which will make use of <sql:update> to execute a SQL DELETE statement to delete one record with id = 103 from the table as follows:

<%@ page import="java.io.*,java.util.*,java.sql.*"%>
<%@ page import="javax.servlet.http.*,javax.servlet.*" %>
<%@ 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:param Tag</title>
</head>
<body>
 
<sql:setDataSource var="snapshot" driver="com.mysql.jdbc.Driver"
     url="jdbc:mysql://localhost:3306/DAVDB"
     user="root"  password="root"/>

<c:set var="empId" value="3333"/>

<sql:update dataSource="${snapshot}" var="count">
  DELETE FROM Employees WHERE Id = ?
  <sql:param value="${empId}" />
</sql:update>

<sql:query dataSource="${snapshot}" 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

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Dinesh Rajput

Dinesh Rajput is the chief editor of a website Dineshonjava, a technical blog dedicated to the Spring and Java technologies. It has a series of articles related to Java technologies. Dinesh has been a Spring enthusiast since 2008 and is a Pivotal Certified Spring Professional, an author of a book Spring 5 Design Pattern, and a blogger. He has more than 10 years of experience with different aspects of Spring and Java design and development. His core expertise lies in the latest version of Spring Framework, Spring Boot, Spring Security, creating REST APIs, Microservice Architecture, Reactive Pattern, Spring AOP, Design Patterns, Struts, Hibernate, Web Services, Spring Batch, Cassandra, MongoDB, and Web Application Design and Architecture. He is currently working as a technology manager at a leading product and web development company. He worked as a developer and tech lead at the Bennett, Coleman & Co. Ltd and was the first developer in his previous company, Paytm. Dinesh is passionate about the latest Java technologies and loves to write technical blogs related to it. He is a very active member of the Java and Spring community on different forums. When it comes to the Spring Framework and Java, Dinesh tops the list!