JSTL SQL <sql:query> Tag

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The <sql:query> tag executes an SQL SELECT statement and saves the result in a scoped variable.

Attribute:

The <sql:query> tag has following attributes:

AttributeDescription RequiredDefault
sqlSQL command to execute (should return a ResultSet)NoBody
dataSourceDatabase connection to use (overrides the default)NoDefault database
maxRowsMaximum number of results to store in the variableNoUnlimited
startRowNumber of the row in the result at which to start recordingNo0
varName of the variable to represent the databaseNoSet default
scopeScope of variable to expose the result from the databaseNoPage

Example:

To start with basic concept, let us create a simple table Employees table in TEST database and create few records in that table as follows:

Step 1:

Open a Command Prompt and change to the installation directory as follows:

C:\>
C:\>cd Program Files\MySQL\bin
C:\Program Files\MySQL\bin>

Step 2:

Login to database as follows

C:\Program Files\MySQL\bin>mysql -u root -p
Enter password: ********
mysql>

Step 3:

Create the table Employee in TEST database as follows:

mysql> use TEST;
mysql> create table Employees
    (
     id int not null,
     age int not null,
     first varchar (255),
     last varchar (255)
    );
Query OK, 0 rows affected (0.08 sec)
mysql>

Create Data Records

Finally you create few records in Employee table as follows:

mysql> INSERT INTO Employees VALUES (100, 18, 'Zara', 'Ali');
Query OK, 1 row affected (0.05 sec)
 
mysql> INSERT INTO Employees VALUES (101, 25, 'Mahnaz', 'Fatma');
Query OK, 1 row affected (0.00 sec)
 
mysql> INSERT INTO Employees VALUES (102, 30, 'Zaid', 'Khan');
Query OK, 1 row affected (0.00 sec)
 
mysql> INSERT INTO Employees VALUES (103, 28, 'Sumit', 'Mittal');
Query OK, 1 row affected (0.00 sec)
 
mysql>

Now let us write a JSP which will make use of <sql:query> to execute a SQL SELECT statement 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:query Tag</title>
</head>
<body>
 
<sql:setDataSource var="snapshot" driver="com.mysql.jdbc.Driver"
     url="jdbc:mysql://localhost/TEST"
     user="root"  password="pass123"/>

<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
100 Zara Ali 18
101 Mahnaz Fatma 25
102 Zaid Khan 30
103 Sumit Mittal 28


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