DELETE przed Batch

src/main/java/bazy/gotowe/postgresql/P10_Batch.java

 package bazy.gotowe.postgresql;
 
-import java.sql.Connection;
-import java.sql.DriverManager;
-import java.sql.PreparedStatement;
-import java.sql.SQLException;
+import java.sql.*;
 
 public class P10_Batch {
 
@@ -11,25 +8,32 @@ public class P10_Batch {
 		int ID = 5000;
 		int ILE = 1000;
 		
-		final String sql = "INSERT INTO locations(location_id, street_address, postal_code, city, country_id)"
+		String deleteSql = "DELETE FROM locations WHERE location_id BETWEEN ? AND ?";
+		final String insertSql = "INSERT INTO locations(location_id, street_address, postal_code, city, country_id)"
 				+ " VALUES(?,?,?,?,?)";
-		
+
 		try(Connection c = DriverManager.getConnection(Ustawienia.URL, Ustawienia.USER, Ustawienia.PASSWD);
-			PreparedStatement stmt = c.prepareStatement(sql)) {
+			PreparedStatement deleteStmt = c.prepareStatement(deleteSql);
+			PreparedStatement insertStmt = c.prepareStatement(insertSql)) {
 
 			c.setAutoCommit(false);  // wyłączamy automatyczne commitowanie - przechodzimy w tryb traksakcji
-			
+
+			deleteStmt.setInt(1, ID);
+			deleteStmt.setInt(2, ID + ILE - 1);
+			int ileD = deleteStmt.executeUpdate();
+			System.out.println("Usunięto " + ileD + "rekordów.");
+
 			System.out.println("start");
 			long poczatek = System.currentTimeMillis();
 			
 			for(int i=0; i<ILE; i++) {
-				stmt.setInt(1, ID + i);
-				stmt.setString(2, "Jasna 23 " + i);
-				stmt.setString(3, "01-234");
-				stmt.setString(4, "Warszawa");
-				stmt.setString(5, "UK");
+				insertStmt.setInt(1, ID + i);
+				insertStmt.setString(2, "Jasna 23 " + i);
+				insertStmt.setString(3, "01-234");
+				insertStmt.setString(4, "Warszawa");
+				insertStmt.setString(5, "UK");
 				
-				stmt.addBatch();
+				insertStmt.addBatch();
 				
 				if(i % 50 == 0) {
 					System.out.println();
@@ -39,7 +43,7 @@ public class P10_Batch {
 			}
 			System.out.print("\n***");
 			// Wykonanie wszystkich poleceń zapamiętanych w batchu
-			stmt.executeBatch();
+			insertStmt.executeBatch();
 		
 			//c.rollback();
 			c.commit();

src/main/java/bazy/gotowe/postgresql/P10_Batch_wersja_bez_batch_do_porownania.java

@@ -10,26 +10,33 @@ public class P10_Batch_wersja_bez_batch_do_porownania {
 	public static void main(String[] args) {
 		int ID = 4000;
 		int ILE = 1000;
-		
-		final String sql = "INSERT INTO locations(location_id, street_address, postal_code, city, country_id)"
+
+		String deleteSql = "DELETE FROM locations WHERE location_id BETWEEN ? AND ?";
+		final String insertSql = "INSERT INTO locations(location_id, street_address, postal_code, city, country_id)"
 				+ " VALUES(?,?,?,?,?)";
-		
+
 		try(Connection c = DriverManager.getConnection(Ustawienia.URL, Ustawienia.USER, Ustawienia.PASSWD);
-			PreparedStatement stmt = c.prepareStatement(sql)) {
+			PreparedStatement deleteStmt = c.prepareStatement(deleteSql);
+			PreparedStatement insertStmt = c.prepareStatement(insertSql)) {
 
 			c.setAutoCommit(false);  // wyłączamy automatyczne commitowanie - przechodzimy w tryb traksakcji
-			
+
+			deleteStmt.setInt(1, ID);
+			deleteStmt.setInt(2, ID + ILE - 1);
+			int ileD = deleteStmt.executeUpdate();
+			System.out.println("Usunięto " + ileD + "rekordów.");
+
 			System.out.println("start");
 			long poczatek = System.currentTimeMillis();
 			
 			for(int i=0; i<ILE; i++) {
-				stmt.setInt(1, ID + i);
-				stmt.setString(2, "Jasna 14/16a lok. " + i);
-				stmt.setString(3, "01-234");
-				stmt.setString(4, "Warszawa");
-				stmt.setString(5, "UK");
-				
-				stmt.executeUpdate();
+				insertStmt.setInt(1, ID + i);
+				insertStmt.setString(2, "Jasna 14/16a lok. " + i);
+				insertStmt.setString(3, "01-234");
+				insertStmt.setString(4, "Warszawa");
+				insertStmt.setString(5, "UK");
+
+				insertStmt.executeUpdate();
 				
 				if(i % 50 == 0) {
 					System.out.println();