diff --git a/src/main/resources/application.properties b/src/main/resources/application.properties
index 7f85f87..22f3728 100644
--- a/src/main/resources/application.properties
+++ b/src/main/resources/application.properties
@@ -18,3 +18,5 @@
 spring.mail.properties.mail.smtp.auth=true
 spring.mail.properties.mail.smtp.ssl.enable=true
 spring.mail.properties.mail.smtp.socketFactory.class=javax.net.ssl.SSLSocketFactory
+
+logging.level.org.springframework.data.redis= DEBUG
diff --git a/src/main/resources/mapper/PeerMapper.xml b/src/main/resources/mapper/PeerMapper.xml
new file mode 100644
index 0000000..b3d4780
--- /dev/null
+++ b/src/main/resources/mapper/PeerMapper.xml
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
+        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
+<mapper namespace="com.example.g8backend.mapper.PeerMapper">
+    <select id="getPeerByPK">
+        SELECT * FROM peers
+        WHERE peer_id = #{peerId} and info_hash = #{infoHash} and passkey = #{passkey}
+    </select>
+    <select id="getPeerByInfoHashAndPeerId">
+        SELECT * FROM peers
+        WHERE info_hash = #{infoHash} and peer_id = #{peerId}
+    </select>
+    <update id="updatePeer">
+        UPDATE peers
+        SET uploaded = #{uploaded}, downloaded = #{downloaded}
+        WHERE peer_id = #{peerId} and info_hash = #{info_hash} and passkey = #{passkey}
+    </update>
+</mapper>