3.2 Method Chaining — MySQL Connectors 1.0

3.2 Цепочки методов

X DevAPI поддерживает ряд современных практик, чтобы упростить работу с операциями CRUD и естественным образом вписаться в современные среды разработки. В этом разделе объясняется, как использовать цепочки методов вместо работы со строками SQL или JSON-структурами.

Следующий пример демонстрирует использование цепочек методов вместо строки SQL при работе с объектами Session. Пример предполагает, что схема test существует и таблица employee существует.

Код MySQL Shell JavaScript

// New method chaining used for executing an SQL SELECT statement
// Recommended way for executing queries
var employees = db.getTable('employee');

var res = employees.select(['name', 'age']).
        where('name like :param').
        orderBy(['name']).
        bind('param', 'm%').execute();

// Traditional SQL execution by passing an SQL string
// It should only be used when absolutely necessary
var result = session.sql('SELECT name, age ' +
  'FROM employee ' +
  'WHERE name like ? ' +
  'ORDER BY name').bind('m%').execute();

Код MySQL Shell Python

# New method chaining used for executing an SQL SELECT statement
# Recommended way for executing queries
employees = db.get_table('employee')

res = employees.select(['name', 'age']) \
        .where('name like :param') \
        .order_by(['name']) \
        .bind('param', 'm%').execute()

# Traditional SQL execution by passing an SQL string
# It should only be used when absolutely necessary
result = session.sql('SELECT name, age ' +
                'FROM employee ' +
                'WHERE name like ? ' +
                'ORDER BY name').bind('m%').execute()

Код Node.js JavaScript

// New method chaining used for executing an SQL SELECT statement
// Recommended way for executing queries
var employees = db.getTable('employee');
var promise = employees.select('name', 'age')
    .where('name like :name')
    .orderBy('name')
    .bind('m%')
    .execute();

// Traditional SQL execution by passing an SQL string
var sqlString = 'SELECT name, age ' +
  'FROM employee ' +
  'WHERE name like ? ' +
  'ORDER BY name';
var promise = db.executeSql(sqlString, 'm%').execute();

Код C#

// New method chaining used for executing an SQL SELECT statement
// Recommended way for executing queries
var employees = db.GetTable("employee");

var res = employees.Select("name", "age")
.Where("name like :param")
.OrderBy("name")
.Bind("param", "m%").Execute();

// Traditional SQL execution by passing an SQL string
// It should only be used when absolutely necessary
var result = session.SQL("SELECT name, age " +
"FROM employee " +
"WHERE name like ? " +
"ORDER BY name").Bind("m%").Execute();

Код Python

# Connector/Python
# New method chaining used for executing an SQL SELECT statement
# Recommended way for executing queries
employees = db.get_table('employee')

res = employees.select(['name', 'age']) \
        .where('name like :param') \
        .order_by(['name']) \
        .bind('param', 'm%').execute()

# Traditional SQL execution by passing an SQL string
# It should only be used when absolutely necessary
result = session.sql('SELECT name, age ' +
                'FROM employee ' +
                'WHERE name like ? ' +
                'ORDER BY name').bind('m%').execute()

Код Java

// New method chaining used for executing an SQL SELECT statement
// Recommended way for executing queries
Table employees = db.getTable("employee");

RowResult res = employees.select("name, age")
  .where("name like :param")
  .orderBy("name")
  .bind("param", "m%").execute();

// Traditional SQL execution by passing an SQL string
// It should only be used when absolutely necessary
SqlResult result = session.sql("SELECT name, age " +
  "FROM employee " +
  "WHERE name like ? " +
  "ORDER BY name").bind("m%").execute();

Код C++

// New method chaining used for executing an SQL SELECT statement
// Recommended way for executing queries
Table employees = db.getTable("employee");

RowResult res = employees.select("name", "age")
  .where("name like :param")
  .orderBy("name")
  .bind("param", "m%").execute();

// Traditional SQL execution by passing an SQL string
// It should only be used when absolutely necessary
RowResult result = session.sql("SELECT name, age "
  "FROM employee "
  "WHERE name like ? "
  "ORDER BY name").bind("m%").execute();