JDBC Statements

 

JDBC Statements

 

Types of Statements in JDBC

JDBC provides three types of statements for executing SQL commands:

1. Statement
2. PreparedStatement
3. CallableStatement

 

1.    Statement

Statement is used to execute simple and static SQL statements that do not require input parameters. The SQL query is written directly as a string and sent to the database for execution. It is commonly used for basic SELECT, INSERT, UPDATE, and DELETE operations.

 

Example:

Statement stat = conc.createStatement();

Stat.executeUpdate(“INSERT into Department values(205, ‘IT’)”);

ResultSet rs = stat.executeQuery("SELECT * FROM Department where deptCode=205");

 

2.   PreparedStatement

PreparedStatement is used to execute parameterized SQL statements. It uses ? as placeholders for values, which are supplied using methods such as setInt() and setString(). It is useful when the same SQL statement needs to be executed with different values.

 

Example:

PreparedStatement ps = conc.prepareStatement("SELECT * FROM Department WHERE DeptCode = ?");

ps.setInt(1, 205);

ResultSet rs = ps.executeQuery();

 

3.   CallableStatement

CallableStatement is used to execute stored procedures in a database. A stored procedure is a set of SQL statements stored and executed on the database server. It can accept input parameters and can also return output parameters.

Step 1: Create a stored procedure in MySQL

Step 2: Call the procedure from Java

 

Procedure:

 

DELIMITER //

 

CREATE PROCEDURE getDepartment(IN val INT)

BEGIN

    SELECT *

    FROM Department

    WHERE DeptCode = val;

END //

 

DELIMITER ;

 

 

CallableStatement cs = conc.prepareCall("{call getDepartment(205)}");

ResultSet rs = cs.executeQuery();