[php] 자주쓰는 sql문 모음

$response = array(); //클라이언트에 보내기 위한 배열 형태 변수

$sql = "DELETE FROM meetupMember
                WHERE moimSeq = '$moimSeq' 
                AND userSeq = '$userSeq'
                AND meetupSeq = '$meetupSeq'
                ";

// $sql = "INSERT INTO meetup (meetupTitle, address, fee, memberCount, moimSeq) 
//                     VALUES ('$meetupTitle', '$address', '$fee', '$memberCount', '$moimSeq')";



if ($conn->query($sql) === TRUE) {

// 방금 생성한 데이터의 고유값 얻는 예시
$last_id = mysqli_insert_id($conn); // 방금 생성한 데이터의 고유값(seq)을 변수에 담는다. -> 모임의 고유값
$message = "Successfully Uploaded";
$success = "1"; // 성공한 경우 1 전달
} else {
$message = "Error: " . $sql."<br>".$conn->error;
$success = "0"; // 실패한 경우 0 전달
}

$conn -> close();

$response["message"] = $message;
$response["success"] = $success;
echo json_encode($response);


// JOIN 사용 예시
$sql = "UPDATE expertInfo LEFT JOIN userInfo ON userInfo.expert_id = expertInfo.expertId
        SET expertService = '$updatedService' WHERE seq = $userSeq";


// query문에서 값을 얻어내는 예시
$memberCountSql = "SELECT COUNT(seq) 
                    FROM member
                    WHERE moimSeq = '$moimSeq'";
$memberCountResult = mysqli_query($conn, $memberCountSql);
$data = mysqli_fetch_array($memberCountResult);
$memberCount = $data[0];


sql = "SELECT selectedExpertId, userIdWhoRequest, chat_rooms.seq AS chatRoomId FROM chat_rooms 
        LEFT JOIN request ON chat_rooms.request_Id = request.seq 
        LEFT JOIN expertInfo ON request.selectedExpertId = expertInfo.expertId 
        -- LEFT JOIN userInfo ON expert.user_id = userInfo.seq 
        WHERE userIdWhoRequest = '$userSeq'";




// 값 배열로 불러오기

$userSeq = $_POST['userSeq'];

$sql = "SELECT * FROM userInfo
        WHERE seq = '$userSeq'";
$result = mysqli_query($conn, $sql);


$arr = array(); // 배열 생성


 while ($row = mysqli_fetch_array($result)) {
     $result_array = array(
         "name" => $row['userName'],
         "profileImage" => $row['userProfileImage'],
         "birthday" => $row['userBirthday'],
         "address" => $row['userAddress'],
         "interest" => $row['userInterest'],
         "intro" => $row['userIntro'],
         "gender" => $row['userGender'],
         "myRoom_id" => $row['myRoom_id']
     );
     $arr = $result_array;
 }



 echo json_encode($arr, JSON_UNESCAPED_UNICODE);
 

 mysqli_close($conn);