Manage data after login

src/main/java/org/to/telegramfinalproject/Database/ChannelDatabase.java

@@ -0,0 +1,76 @@
+package org.to.telegramfinalproject.Database;
+
+import org.to.telegramfinalproject.Models.Channel;
+import org.to.telegramfinalproject.Models.Group;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+
+public class ChannelDatabase {
+    public static List<Channel> getChannelsByUser(UUID internalUuid) {
+        List<Channel> channels = new ArrayList<>();
+
+        String sql = """
+            SELECT c.* FROM channels c
+            JOIN channel_subscribers cs ON c.internal_uuid = cs.channel_id
+            WHERE cs.user_id = ?
+        """;
+
+        try (Connection conn = ConnectionDb.connect();
+             PreparedStatement stmt = conn.prepareStatement(sql)) {
+
+            stmt.setObject(1, internalUuid);
+            ResultSet rs = stmt.executeQuery();
+
+            while (rs.next()) {
+                Channel channel = new Channel();
+
+                channel.setInternal_uuid(UUID.fromString(rs.getString("internal_uuid")));
+                channel.setChannel_id(rs.getString("channel_id"));
+                channel.setChannel_name(rs.getString("channel_name"));
+                channel.setCreator_id(UUID.fromString(rs.getString("creator_id")));
+                channel.setImage_url(rs.getString("image_url"));
+                channel.setDescription(rs.getString("description"));
+                channel.setCreated_at(rs.getTimestamp("created_at").toLocalDateTime());
+
+                channels.add(channel);
+            }
+
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+
+        return channels;
+    }
+
+
+    public static List<Channel> searchChannels(String keyword) {
+        List<Channel> result = new ArrayList<>();
+        String sql = "SELECT * FROM channels WHERE channel_name ILIKE ? OR channel_id ILIKE ?";
+        try (Connection conn = ConnectionDb.connect();
+             PreparedStatement stmt = conn.prepareStatement(sql)) {
+            stmt.setString(1, "%" + keyword + "%");
+            ResultSet rs = stmt.executeQuery();
+            while (rs.next()) {
+                Channel channel = new Channel(
+                        UUID.fromString(rs.getString("internal_uuid")),
+                        rs.getString("channel_name"),
+                        UUID.fromString(rs.getString("creator_id")),
+                        rs.getTimestamp("created_at").toLocalDateTime()
+                );
+                channel.setChannel_id(rs.getString("channel_id"));
+                channel.setImage_url(rs.getString("image_url"));
+                channel.setDescription(rs.getString("description"));
+                result.add(channel);
+            }
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+        return result;
+    }
+}