In this example we shall show you how to handle SQL Warnings in Java. To handle SQL Warnings one should perform the following steps:
- Load the JDBC driver, using the
forName(String className)API method of the Class. In this example we use the Oracle JDBC driver. - Create a Connection to the database. Invoke the
getConnection(String url, String user, String password)API method of the DriverManager to create the connection. - Get the SQLWarning risen while connecting to the database, using the
getWarnings()API method of the Connection. - Check the connectionWarning, with
getMessage(),getSQLState(),getErrorCode()and then get the next warning withgetNextWarning()API methods of the SQLWarning. - Execute an SQL Statement, which returns a ResultSet object. For each row of the ResultSet get the SQLWarnings, using the
getWarnings()API method of the ResultSet. - Check on the resultsetWarning with the
getMessage(),getSQLState(),getErrorCode()and then get the next warning withgetNextWarning()API methods of the ResultSet,
as described in the code snippet below.
package com.javacodegeeks.snippets.core;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.SQLWarning;
import java.sql.Statement;
public class SQLWarning {
public static void main(String[] args) {
Connection connection = null;
try {
// Load the Oracle JDBC driver
String driverName = "oracle.jdbc.driver.OracleDriver";
Class.forName(driverName);
// Create a connection to the database
String serverName = "localhost";
String serverPort = "1521";
String sid = "mySchema";
String url = "jdbc:oracle:thin:@" + serverName + ":" + serverPort + ":" + sid;
String username = "username";
String password = "password";
connection = DriverManager.getConnection(url, username, password);
System.out.println("Successfully Connected to the database!");
} catch (ClassNotFoundException e) {
System.out.println("Could not find the database driver " + e.getMessage());
} catch (SQLException e) {
System.out.println("Could not connect to the database " + e.getMessage());
}
try {
// Get warnings risen while connecting to the database
SQLWarning connectionWarning = connection.getWarnings();
while (connectionWarning != null) {
String warningMessage = connectionWarning.getMessage();
String warningSQLState = connectionWarning.getSQLState();
int warningErrorCode = connectionWarning.getErrorCode();
System.out.println("Connection warning : " + warningErrorCode +" Message : " + warningMessage + " SQL state " + warningSQLState);
connectionWarning = connectionWarning.getNextWarning();
}
// Create a statement
Statement statement = connection.createStatement();
// Use the statement...
// Get warnings risen while using the statement
SQLWarning statementWarning = statement.getWarnings();
if (statementWarning != null) {
String warningMessage = statementWarning.getMessage();
String warningSQLState = statementWarning.getSQLState();
int warningErrorCode = statementWarning.getErrorCode();
System.out.println("Statement warning : " + warningErrorCode +" Message : " + warningMessage + " SQL state " + warningSQLState);
statementWarning = statementWarning.getNextWarning();
}
// Get the result set from the statement
ResultSet resultSet = statement.executeQuery("SELECT * FROM test_table");
while (resultSet.next()) {
// Use result set ...
// Get warnings on the current row of the result set
SQLWarning resultsetWarning = resultSet.getWarnings();
if (resultsetWarning != null) {
String warningMessage = resultsetWarning.getMessage();
String warningSQLState = resultsetWarning.getSQLState();
int warningErrorCode = resultsetWarning.getErrorCode();
System.out.println("Resultset warning : " + warningErrorCode +" Message : " + warningMessage + " SQL state " + warningSQLState);
resultsetWarning = resultsetWarning.getNextWarning();
}
}
} catch (SQLException e) {
}
}
}
Output:
Successfully Connected to the database!
This was an example of how to handle SQL Warnings in Java.
