Java/Database SQL JDBC/SQL Warning

Determining If a SQL Warning Occurred

   <source lang="java">
 

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 Main {

 public static void main(String[] argv) throws Exception {
   String driverName = "com.jnetdirect.jsql.JSQLDriver";
   Class.forName(driverName);
   String serverName = "127.0.0.1";
   String portNumber = "1433";
   String mydatabase = serverName + ":" + portNumber;
   String url = "jdbc:JSQLConnect://" + mydatabase;
   String username = "username";
   String password = "password";
   Connection connection = DriverManager.getConnection(url, username, password);
   try {
     SQLWarning warning = connection.getWarnings();
     while (warning != null) {
       String message = warning.getMessage();
       String sqlState = warning.getSQLState();
       int errorCode = warning.getErrorCode();
       warning = warning.getNextWarning();
     }
     Statement stmt = connection.createStatement();
     warning = stmt.getWarnings();
     if (warning != null) {
     }
     ResultSet resultSet = stmt.executeQuery("SELECT * FROM my_table");
     while (resultSet.next()) {
       warning = resultSet.getWarnings();
       if (warning != null) {
       }
     }
   } catch (SQLException e) {
   }
 }

}

 </source>
   
  
 
  

Get Next SQL Warning()

   <source lang="java">

import java.sql.Connection; import java.sql.DataTruncation; import java.sql.DriverManager; import java.sql.SQLException; import java.sql.SQLWarning; import java.sql.Statement; public class DemoDataTruncation {

 public static void displayError(DataTruncation dataTruncation) {
   System.out.println("Data truncation error: ");
   System.out.println(dataTruncation.getDataSize() + " bytes should have been ");
   if (dataTruncation.getRead()) {
     System.out.println("Read (Error:) ");
   } else {
     System.out.println("Written (Error:) ");
   }
   System.out.println(dataTruncation.getTransferSize()
       + " number of bytes of data actually transferred.");
 }
 public static void displayError(SQLWarning warning) {
   while (warning != null) {
     if (warning instanceof DataTruncation) {
       displayError((DataTruncation) warning);
     } else {
       System.out.println(" Warning: " + warning.getMessage());
     }
     warning = warning.getNextWarning();
   }
 }
 public static Connection getMySQLConnection() throws Exception {
   String driver = "org.gjt.mm.mysql.Driver";
   String url = "jdbc:mysql://localhost/databaseName";
   String username = "root";
   String password = "root";
   Class.forName(driver);
   return DriverManager.getConnection(url, username, password);
 }
 public static void main(String[] args) throws Exception {
   Connection conn = getMySQLConnection();
   Statement stmt = null;
   try {
     stmt = conn.createStatement();
     stmt.executeUpdate("DELETE FROM animals_table");
     displayError(stmt.getWarnings());
     stmt.executeUpdate("INSERT INTO animals_table(id, name)"
         + "VALUES(1, "NameLongerThanColumnLengthInDatabase")");
     displayError(stmt.getWarnings());
   } catch (DataTruncation dt) {
     displayError(dt);
     dt.printStackTrace();
   } catch (SQLException se) {
     System.out.println("Database error message: " + se.getMessage());
   } catch (Exception e) {
     e.printStackTrace();
   } finally {
     stmt.close();
     conn.close();
   }
 }

}

 </source>
   
  
 
  

Get SqlWarning Statement object

   <source lang="java">
 

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) {
   try {
     Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();
     String jdbcUrl = "jdbc:oracle:thin:@localhost:1521:ORCL";
     Connection conn = DriverManager.getConnection(jdbcUrl, "yourName", "mypwd");
     Statement stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE);
     SQLWarning sw = null;
     ResultSet rs = stmt.executeQuery("Select * from employees");
     sw = stmt.getWarnings();
     System.out.println(sw.getMessage());
     while (rs.next()) {
       System.out.println("Employee name: " + rs.getString(2));
     }
     rs.previous();
     rs.updateString("name", "Jon");
   } catch (SQLException se) {
     System.out.println("SQLException occurred: " + se.getMessage());
   } catch (Exception e) {
     e.printStackTrace();
   }
 }

}

 </source>
   
  
 
  

Raising Custom Sql Warning

   <source lang="java">

import java.sql.SQLException; import java.sql.SQLWarning; public class RasingCustomSqlWarning {

 public static void main(String[] args) {
   try {
     throwWarning();
   } catch (SQLException e) {
     System.err.println("An SQL exception occurred: " + e);
     e.printStackTrace();
     while ((e = e.getNextException()) != null) {
       System.err.println("Contained reason: " + e);
     }
   }
 }
 private static void throwWarning() throws SQLException {
   SQLWarning rootWarning = new SQLWarning("Outter warning");
   SQLWarning containedWarning = new SQLWarning("Inner warning");
   rootWarning.setNextWarning(containedWarning);
   throw rootWarning;
 }

}

 </source>