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Running the COPY FROM STDIN Statement to Import Data/
Example 2: Migrating Data from MY
Updated on 2023-10-23 GMT+08:00
Example 2: Migrating Data from MY
The following example shows how to use CopyManager to migrate data from MY to GaussDB.
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import java.io.StringReader; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import org.postgresql.copy.CopyManager; import org.postgresql.core.BaseConnection; public class Migration{ public static void main(String[] args) { String url = new String("jdbc:postgresql://localhost:8000/postgres"); // URL of the database String user = new String("username"); // GaussDB database user name String pass = new String("passwd"); // GaussDB database password String tablename = new String("migration_table_1"); // Table information String delimiter = new String("|"); // Delimiter String encoding = new String("UTF8"); // Character set String driver = "org.postgresql.Driver"; StringBuffer buffer = new StringBuffer(); // Buffer to store formatted data try { // Obtain the query result set of the source database. ResultSet rs = getDataSet(); // Traverse the result set and obtain records row by row. // The values of columns in each record are separated by the specified delimiter and end with a linefeed, forming strings. // Add the strings to the buffer. while (rs.next()) { buffer.append(rs.getString(1) + delimiter + rs.getString(2) + delimiter + rs.getString(3) + delimiter + rs.getString(4) + "\n"); } rs.close(); try { // Connect to the target database. Class.forName(driver); Connection conn = DriverManager.getConnection(url, user, pass); BaseConnection baseConn = (BaseConnection) conn; baseConn.setAutoCommit(false); // Initialize the table. String sql = "Copy " + tablename + " from STDIN with (DELIMITER " + "'" + delimiter + "'" +","+ " ENCODING " + "'" + encoding + "'"); // Commit data in the buffer. CopyManager cp = new CopyManager(baseConn); StringReader reader = new StringReader(buffer.toString()); cp.copyIn(sql, reader); baseConn.commit(); reader.close(); baseConn.close(); } catch (ClassNotFoundException e) { e.printStackTrace(System.out); } catch (SQLException e) { e.printStackTrace(System.out); } } catch (Exception e) { e.printStackTrace(); } } //******************************** // Return the query result set from the source database. //********************************* private static ResultSet getDataSet() { ResultSet rs = null; try { Class.forName("com.MY.jdbc.Driver").newInstance(); Connection conn = DriverManager.getConnection("jdbc:MY://10.119.179.227:3306/jack?useSSL=false&allowPublicKeyRetrieval=true", "jack", "xxxxxxxxx"); Statement stmt = conn.createStatement(); rs = stmt.executeQuery("select * from migration_table"); } catch (SQLException e) { e.printStackTrace(); } catch (Exception e) { e.printStackTrace(); } return rs; } } |
Parent topic: Running the COPY FROM STDIN Statement to Import Data
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