PDF(美制信函) - 1.4Mb
PDF (A4) - 1.4Mb
之前的所有示例都使用了 Session 对象的 getSchema()
或 getDefaultSchema()
方法,它们返回一个 Schema 对象。您可以使用此 Schema 对象访问集合和表。大多数示例都利用了 X DevAPI 将所有对象构造链接在一起的能力,使您能够在一行中获得 Schema 对象。例如
schema = mysqlx.getSession(...).getSchema();
此对象链等效于以下内容,区别在于省略了中间步骤
session = mysqlx.getSession();
schema = session.getSchema().
没有要求始终链接调用,直到您获得 Schema 对象,也不一定是您想要的。例如,如果您想使用 Session 对象调用 Session 对象方法 getSchemas()
,则无需导航到 Schema。例如
session = mysqlx.getSession(); session.getSchemas().
在此示例中,mysqlx.getSession()
函数用于打开一个 Session。然后,使用 Session.getSchemas()
函数获取所有可用模式的列表并将其打印到控制台。
MySQL Shell JavaScript 代码
// Connecting to MySQL and working with a Session
var mysqlx = require('mysqlx');
// Connect to a dedicated MySQL server using a connection URI
var mySession = mysqlx.getSession('user:password@localhost');
// Get a list of all available schemas
var schemaList = mySession.getSchemas();
print('Available schemas in this session:\n');
// Loop over all available schemas and print their name
for (index in schemaList) {
print(schemaList[index].name + '\n');
}
mySession.close();
MySQL Shell Python 代码
# Connecting to MySQL and working with a Session
from mysqlsh import mysqlx
# Connect to a dedicated MySQL server using a connection URI
mySession = mysqlx.get_session('user:password@localhost')
# Get a list of all available schemas
schemaList = mySession.get_schemas()
print('Available schemas in this session:\n')
# Loop over all available schemas and print their name
for schema in schemaList:
print('%s\n' % schema.name)
mySession.close()
Node.js JavaScript 代码
// Connecting to MySQL and working with a Session
var mysqlx = require('@mysql/xdevapi');
// Connect to a dedicated MySQL server using a connection URI
mysqlx
.getSession('user:password@localhost')
.then(function (mySession) {
// Get a list of all available schemas
return mySession.getSchemas();
})
.then(function (schemaList) {
console.log('Available schemas in this session:\n');
// Loop over all available schemas and print their name
schemaList.forEach(function (schema) {
console.log(schema.getName() + '\n');
});
});
C# 代码
// Connect to a dedicated MySQL server node using a connection URI
var mySession = MySQLX.GetSession("mysqlx://user:password@localhost:33060");
// Get a list of all available schemas
var schemaList = mySession.GetSchemas();
Console.WriteLine("Available schemas in this session:");
// Loop over all available schemas and print their name
foreach (var schema in schemaList)
{
Console.WriteLine(schema.Name);
}
mySession.Close();
Python 代码
# Connector/Python
# Connecting to MySQL and working with a Session
from mysqlsh import mysqlx
# Connect to a dedicated MySQL server using a connection URI
mySession = mysqlx.get_session('user:password@localhost')
# Get a list of all available schemas
schemaList = mySession.get_schemas()
print('Available schemas in this session:\n')
# Loop over all available schemas and print their name
for schema in schemaList:
print('%s\n' % schema.name)
mySession.close()
Java 代码
import java.util.List;
import com.mysql.cj.xdevapi.*;
// Connecting to MySQL and working with a Session
// Connect to a dedicated MySQL server using a connection URI
Session mySession = new SessionFactory().getSession("mysqlx://localhost:33060/test?user=user&password=password");
// Get a list of all available schemas
List<Schema> schemaList = mySession.getSchemas();
System.out.println("Available schemas in this session:");
// Loop over all available schemas and print their name
for (Schema schema : schemaList) {
System.out.println(schema.getName());
}
mySession.close();
C++ 代码
#include <mysqlx/xdevapi.h>
// Connecting to MySQL and working with a Session
// Connect to a dedicated MySQL server using a connection URI
string url = "mysqlx://localhost:33060/test?user=user&password=password";
{
Session mySession(url);
// Get a list of all available schemas
std::list<Schema> schemaList = mySession.getSchemas();
cout << "Available schemas in this session:" << endl;
// Loop over all available schemas and print their name
for (Schema schema : schemaList) {
cout << schema.getName() << endl;
}
}