Updated DatabaseManager

Made sql statements into transaction statements for increased stability. Converted "temp" table into a fully temporary table. Reused a single String variable for sql queries instead of one variable per statement.

helpmehelpapplication/src/main/java/ntnu/sytemutvikling/team6/models/DatabaseManager.java

@@ -59,7 +59,7 @@ public DatabaseManager() {
      */
 
     public void createCharitiesTable() {
-        String sql_create_main_table = """
+        String sql_query = """
                 CREATE TABLE IF NOT EXISTS charities (
                 org_number VARCHAR(100) PRIMARY KEY,
                 name VARCHAR(255),
@@ -71,7 +71,7 @@ url VARCHAR(255),
         try (Connection conn = DriverManager.getConnection(databaseURL, username, password);
              Statement s = conn.createStatement()) {
 
-            s.execute(sql_create_main_table);
+            s.execute(sql_query);
         } catch (SQLException e) {
             e.printStackTrace();
             throw new RuntimeException("Error creating tables.");
@@ -95,11 +95,12 @@ url VARCHAR(255),
      */
 
     public void updateCharities(List<APICharityData> charities) {
-
-        try (Connection conn = DriverManager.getConnection(databaseURL, username, password))
-             {
+            Connection conn = null;
+        try {
+                 conn = DriverManager.getConnection(databaseURL, username, password);
+                 conn.setAutoCommit(false);
                  // Inserts objects values into charities
-                 String sql_update = """
+                 String sql_query = """
                             INSERT INTO charities (org_number, name, status, url, is_pre_approved)
                             VALUES (?, ?, ?, ?, ?)
                             ON DUPLICATE KEY UPDATE
@@ -109,59 +110,73 @@ INSERT INTO charities (org_number, name, status, url, is_pre_approved)
                               is_pre_approved = VALUES(is_pre_approved)
                 """;
 
-                 PreparedStatement s = conn.prepareStatement(sql_update);
-
-                 for (APICharityData charity : charities) {
-                s.setString(1, charity.getOrg_number().replaceAll("\\s", ""));
-                s.setString(2, charity.getName());
-                s.setString(3, charity.getStatus());
-                s.setString(4, charity.getUrl());
-                s.setBoolean(5, charity.getIs_pre_approved());
-
-                s.addBatch();
+                 try (PreparedStatement s = conn.prepareStatement(sql_query)) {
+                     for (APICharityData charity : charities) {
+                         s.setString(1, charity.getOrg_number().replaceAll("\\s", ""));
+                         s.setString(2, charity.getName());
+                         s.setString(3, charity.getStatus());
+                         s.setString(4, charity.getUrl());
+                         s.setBoolean(5, charity.getIs_pre_approved());
+
+                         s.addBatch();
+                 }
+                     s.executeBatch();
             }
-            s.executeBatch();
 
-             // Temporary table for parity check
-            String sql_drop_temp_table = "DROP TABLE IF EXISTS temp";
-            PreparedStatement drop_temp_table = conn.prepareStatement(sql_drop_temp_table);
-            drop_temp_table.execute();
 
-            String sql_create_temp_table = "CREATE TABLE temp (org_number VARCHAR(100) PRIMARY KEY)";
-            PreparedStatement temp_create = conn.prepareStatement(sql_create_temp_table);
-            temp_create.execute();
+             // Temporary table for parity check
+            sql_query = "CREATE TEMPORARY TABLE temp (org_number VARCHAR(100) PRIMARY KEY)";
+                 try (PreparedStatement temp_create = conn.prepareStatement(sql_query)) {
+                     temp_create.execute();
+                 }
 
             String sql_update_temp_table = "INSERT INTO temp (org_number) VALUES (?)";
-            PreparedStatement temp_update = conn.prepareStatement(sql_update_temp_table);
-            for (APICharityData charity : charities) {
-                temp_update.setString(1, charity.getOrg_number().replaceAll("\\s", ""));
-                temp_update.addBatch();
-            }
-            temp_update.executeBatch();
+                 try (PreparedStatement temp_update = conn.prepareStatement(sql_update_temp_table)) {
+                     for (APICharityData charity : charities) {
+                         temp_update.setString(1, charity.getOrg_number().replaceAll("\\s", ""));
+                         temp_update.addBatch();
+                     }
+                     temp_update.executeBatch();
+                 }
+
+
 
             // Removes records not found in the list from charities table
-            String sql_delete_old_records = """
+            sql_query = """
                     DELETE FROM charities c
                     WHERE NOT EXISTS (
                     SELECT 1
                     FROM temp t
                     WHERE c.org_number = t.org_number
                     )
                     """;
-            PreparedStatement delete_old_records = conn.prepareStatement(sql_delete_old_records);
-            delete_old_records.execute();
-
-            // Deletes temporary table
-            String sql_delete_temp_table = "DROP TABLE IF EXISTS temp";
-            PreparedStatement delete_temp_table = conn.prepareStatement(sql_delete_temp_table);
-            delete_temp_table.execute();
 
+                 try (PreparedStatement delete_old_records = conn.prepareStatement(sql_query)){
+                     delete_old_records.execute();
+                 }
 
+            conn.commit();
+        } catch (SQLException e) {
 
+            if (conn != null) {
+                try {
+                    conn.rollback();
+                } catch (SQLException ex) {
+                    ex.printStackTrace();
+                }
+            }
 
-        } catch (SQLException e) {
             e.printStackTrace();
             throw new RuntimeException("ERROR: Something went wrong during updating charities table.");
+        } finally {
+            if (conn != null) {
+                try {
+                    conn.setAutoCommit(true);
+                    conn.close();
+                } catch (SQLException e) {
+                    e.printStackTrace();
+                }
+            }
         }
 
     }