From 9abe83b21309bdde92a3f296fb54c83dcc26d680 Mon Sep 17 00:00:00 2001
From: Rsl1122 <djrapitops@hotmail.com>
Date: Sun, 15 Sep 2019 16:22:36 +0300
Subject: [PATCH] Fixed average KDR / Player query

- The query was causing SQLException on some MySQL versions
- The query did not take into account players who haven't been killed
- The query did not take into account players with no kills
---
 .../database/queries/objects/KillQueries.java | 22 ++++++++++++++-----
 .../plan/storage/database/DatabaseTest.java   | 12 ++++++++++
 2 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/Plan/common/src/main/java/com/djrapitops/plan/storage/database/queries/objects/KillQueries.java b/Plan/common/src/main/java/com/djrapitops/plan/storage/database/queries/objects/KillQueries.java
index aae6e66a7..4ba7c32c5 100644
--- a/Plan/common/src/main/java/com/djrapitops/plan/storage/database/queries/objects/KillQueries.java
+++ b/Plan/common/src/main/java/com/djrapitops/plan/storage/database/queries/objects/KillQueries.java
@@ -22,6 +22,7 @@ import com.djrapitops.plan.storage.database.queries.Query;
 import com.djrapitops.plan.storage.database.queries.QueryStatement;
 import com.djrapitops.plan.storage.database.sql.tables.KillsTable;
 import com.djrapitops.plan.storage.database.sql.tables.SessionsTable;
+import com.djrapitops.plan.storage.database.sql.tables.UserInfoTable;
 import com.djrapitops.plan.storage.database.sql.tables.UsersTable;
 
 import java.sql.PreparedStatement;
@@ -179,10 +180,11 @@ public class KillQueries {
                 AND + KillsTable.DATE + ">=?" +
                 AND + KillsTable.DATE + "<=?" +
                 GROUP_BY + KillsTable.VICTIM_UUID;
-        String sql = SELECT + "AVG(CAST(kills AS double)/CAST(deaths AS double)) as kdr" +
-                FROM + '(' + selectKillCounts + ") q1" +
-                INNER_JOIN + '(' + selectDeathCounts + ") q2 on q1." + KillsTable.KILLER_UUID + "=q2." + KillsTable.VICTIM_UUID +
-                WHERE + "deaths!=0";
+        String sql = SELECT + "u." + UserInfoTable.USER_UUID + ",kills, deaths" +
+                FROM + UserInfoTable.TABLE_NAME + " u" +
+                LEFT_JOIN + '(' + selectKillCounts + ") q1 on q1." + KillsTable.KILLER_UUID + "=u." + UserInfoTable.USER_UUID +
+                LEFT_JOIN + '(' + selectDeathCounts + ") q2 on q2." + KillsTable.VICTIM_UUID + "=u." + UserInfoTable.USER_UUID +
+                WHERE + "u." + UserInfoTable.SERVER_UUID + "=?";
 
         return new QueryStatement<Double>(sql) {
             @Override
@@ -193,11 +195,21 @@ public class KillQueries {
                 statement.setString(4, serverUUID.toString());
                 statement.setLong(5, after);
                 statement.setLong(6, before);
+                statement.setString(7, serverUUID.toString());
             }
 
             @Override
             public Double processResults(ResultSet set) throws SQLException {
-                return set.next() ? set.getDouble("kdr") : 0.0;
+                double totalKDR = 0.0;
+                int playerCount = 0;
+                while (set.next()) {
+                    int kills = set.getInt("kills");
+                    int deaths = set.getInt("deaths");
+                    System.out.println("K:" + kills + " D:" + deaths);
+                    totalKDR += (double) kills / (deaths > 0 ? deaths : 1);
+                    playerCount++;
+                }
+                return totalKDR / (playerCount > 0 ? playerCount : 1);
             }
         };
     }
diff --git a/Plan/common/src/test/java/com/djrapitops/plan/storage/database/DatabaseTest.java b/Plan/common/src/test/java/com/djrapitops/plan/storage/database/DatabaseTest.java
index ad577efc1..49b2af637 100644
--- a/Plan/common/src/test/java/com/djrapitops/plan/storage/database/DatabaseTest.java
+++ b/Plan/common/src/test/java/com/djrapitops/plan/storage/database/DatabaseTest.java
@@ -1413,6 +1413,18 @@ public interface DatabaseTest {
         assertNotEquals(Collections.emptyList(), result);
     }
 
+    @Test
+    default void kdrCastAsDoubleDoesNotCauseExceptions() {
+        sessionsAreStoredWithAllData();
+        db().executeTransaction(new PlayerServerRegisterTransaction(player2UUID, () -> 123456789L, "Test", serverUUID()));
+
+        Long killCount = db().query(KillQueries.playerKillCount(0L, System.currentTimeMillis(), serverUUID()));
+        assertEquals(2, killCount); // Ensure the kills were saved
+
+        Double result = db().query(KillQueries.averageKDR(0L, System.currentTimeMillis(), serverUUID()));
+        assertEquals(1.0, result, 0.1);
+    }
+
     @PluginInfo(name = "ConditionalExtension")
     class ConditionalExtension implements DataExtension {