Admin: 1 версия

2010-06-01T06:35:18Z

1 версия

в 18:01, 31 мая 2010

2010-05-31T18:01:44Z

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== 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>

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Admin: 1 версия

в 18:01, 31 мая 2010