我想同时同步和更新本地数据库和远程数据库。所有者在不同的地方有四家餐厅（A，B，C，D）。他在所有四家餐厅保持相同的产品价格和质量。因此，他使用远程数据库来更改价格，该价格曾经影响所有分支机构的更改后的价格。所有四个分支和远程服务器都具有相同的数据库结构和相同的表（即：分支还具有记录的另一个分支。每个分支的每个表都由id和branch字段唯一标识（{{1} }。
样品表（购买）
id + branch as composite key我有以下代码从本地数据库中提取新添加的记录和更新的记录（具有字段+----+--------+------------+------------+-----+--------------------+---------------------+
| id | branch | item | unit_price | qty | added_on | last_updated |
+----+--------+------------+------------+-----+--------------------+---------------------+
| 1 | A | Pizza | 800 | 5 |2018-12-05T15:47:54 | 2018-05-11T15:47:54 |
+----+--------+------------+------------+-----+--------------------+---------------------+
| 2 | A | Chicken | 350 | 5 |2018-12-05T15:49:54 | 2018-05-11T15:50:54 |
+----+--------+------------+------------+-----+--------------------+---------------------+
| 2 | B | cappuccino | 280 | 7 |2018-12-05T15:47:24 | 2018-05-11T15:47:24 |
+----+--------+------------+------------+-----+--------------------+---------------------+
和added_on），然后使用计时器上载并导入到远程数据库中。这里从本地数据库提取记录的检查时间存储在一个文件中，计时器将使用该文件。
现在，要更新每个分支中的本地数据库（下载其他分支记录），如何从远程服务器上下载新插入的记录和更新的记录？
远程服务器上的php脚本（要在远程数据库上插入）（execute.php）
last_updated文件上传器（upload.php）
<?php
try
{
$connect = mysqli_connect("localhost", "username", "password", "database");
$query = '';
$table_data = '';
$filename = "app_restaurant.json";
$data = file_get_contents($filename);
$array = json_decode($data, true);
foreach ($array as $set)
{
$tblName = $set['tableName'];
if (sizeof($set['rows']) > 0)
{
$query = '';
$colList = array();
$valList = array();
// Get list of column names
foreach ($set['rows'][0] as $colName => $dataval)
{
$colList[] = "`" . $colName . "`";
}
$query .= "INSERT INTO `" . $tblName . "` \n";
$query .= "(" . implode(",", $colList) . ")\nVALUES\n";
// Go through the rows for this table.
foreach ($set['rows'] as $idx => $row)
{
$colDataA = array();
// Get the data values for this row.
foreach ($row as $colName => $colData)
{
$colDataA[] = "'" . $colData . "'";
}
$valList[] = "(" . implode(",", $colDataA) . ")";
}
// Add values to the query.
$query .= implode(",\n", $valList) . "\n";
// If id column present, add ON DUPLICATE KEY UPDATE clause
if (in_array("`id`", $colList))
{
$query .= "ON DUPLICATE KEY UPDATE\n\t";
$tmp = array();
foreach ($colList as $idx => $colName)
{
//$tmp[] = $colName." = new.".$colName." ";
// Changed the following line to get value from current insert row data
$tmp[] = $colName . " = VALUES(" . $colName . ") ";
}
$query .= implode(",", $tmp) . "\n";
}
else
{
echo "<p><b>`id`</b> column not found. <i>ON DUPLICATE KEY UPDATE</i> clause <b>NOT</b> added.</p>\n";
echo "<p>Columns Found:<pre>" . print_r($colList, true) . "</pre></p>\n";
}
echo "<p>Insert query:<pre>$query</pre></p>";
$r = mysqli_query($connect, $query);
echo mysqli_errno($connect) . ": " . mysqli_error($connect) . "\n";
echo "<h1>" . mysqli_affected_rows($connect) . " Rows appended in .$tblName.</h1>";
}
else
{
echo "<p>No rows to insert for .$tblName.</p>";
}
}
}
catch (Exception $e)
{
echo $e->getMessage();
}
?>
1。从本地数据库创建JSON文件
<?php
$filepath = $_FILES["file"]["tmp_name"];
move_uploaded_file($filepath,"app_restaurant.json");
?>
2。将JSON文件上传到服务器
private void btnExportJson_Click(object sender, EventArgs e)
{
string filePath = @"C:\Users\testeam-PC\Desktop\app_restaurant.json";
if(File.Exists(filePath))
{
MessageBox.Show("Sorry! The file is already exists, Please restart the operation","File Exists");
File.Delete(filePath);
}
else
{
MySQL mysql = new MySQL();
var source_result = false;
source_result = mysql.check_connection(myConString);
if (source_result == false)
{
MessageBox.Show("Sorry! Unable to connect with XAMP / WAMP or MySQL.\n Please make sure that MySQL is running.", "Local Database Connection Failure");
}
else
{
// MessageBox.Show("Connected");
int count = 0;
using (var connection = new MySqlConnection(myConString))
{
connection.Open();
// get the names of all tables in the chosen database
var tableNames = new List<string>();
using (var command = new MySqlCommand(@"SELECT table_name FROM information_schema.tables where table_schema = @database", connection))
{
command.Parameters.AddWithValue("@database", "app_restaurant");
using (var reader = command.ExecuteReader())
{
while (reader.Read())
tableNames.Add(reader.GetString(0));
}
}
// open a JSON file for output; use the streaming JsonTextWriter interface to avoid high memory usage
using (var streamWriter = new StreamWriter(filePath))
// For seperate lines may be huge capacity
using (var jsonWriter = new JsonTextWriter(streamWriter) { Formatting = Newtonsoft.Json.Formatting.Indented, Indentation = 2, IndentChar = ' ' })
//using (var jsonWriter = new JsonTextWriter(streamWriter) )
{
// one array to hold all tables
jsonWriter.WriteStartArray();
foreach (var tableName in tableNames)
{
//MessageBox.Show(tableName);
count += 1;
// an object for each table
jsonWriter.WriteStartObject();
jsonWriter.WritePropertyName("tableName");
jsonWriter.WriteValue(tableName);
jsonWriter.WritePropertyName("rows");
// an array for all the rows in the table
jsonWriter.WriteStartArray();
// select all the data from each table
using (var command = new MySqlCommand(@"SELECT * FROM " + tableName + " WHERE (last_updated >= '" + local_checked_time + "') OR (added_on >= '" + local_checked_time + "')", connection))
using (var reader = command.ExecuteReader())
{
while (reader.Read())
{
// write each row as a JSON object
jsonWriter.WriteStartObject();
for (int i = 0; i < reader.FieldCount; i++)
{
jsonWriter.WritePropertyName(reader.GetName(i));
jsonWriter.WriteValue(reader.GetValue(i));
}
jsonWriter.WriteEndObject();
}
}
jsonWriter.WriteEndArray();
jsonWriter.WriteEndObject();
}
jsonWriter.WriteEndArray();
MessageBox.Show("Totally " + count + " tables circulated", "Success");
btnUploadToServer.Enabled = true;
// Application.Exit();
//btnUploadToServer_Click(sender, e);
}
}
}
}
}
3。执行文件
private void btnUploadToServer_Click(object sender, EventArgs e)
{
bool connection = NetworkInterface.GetIsNetworkAvailable();
if (connection == true)
{
//MessageBox.Show("Internet Available");
try
{
using (WebClient client = new WebClient())
{
string filePath = @"C:\Users\testeam-PC\Desktop\app_restaurant.json";
var myUri = new Uri(@"http://youraddress.com/path/upload.php");
client.UploadFile(myUri, filePath);
client.Credentials = CredentialCache.DefaultCredentials;
}
}
catch (Exception err)
{
MessageBox.Show(err.Message);
}
MessageBox.Show("Successfully Uploaded", "Success");
btnExecuteURL.Enabled = true;
// btnExecuteURL_Click(sender, e);
}
else
{
MessageBox.Show("There is no internet connection.\n Please make sure that you have an internet connection.", "No Internet");
}
}