SQL to SequoiaDB shell to Java
SequoiaDB 的查询用 json(bson)对象表示,下表以例子的形式显示了 SQL 语句,SequoiaDB shell 语句和 SequoiaDB Java 驱动程序语法之间的对照。
SQL | SequoiaDB shell | Java Driver |
---|---|---|
insert into employee( a, b) values( 1, -1 ) | db.sample.employee.insert( { a: 1, b: -1 } ) | employee.insert( “{ ‘a’: 1, ‘b’: -1 }” ) |
select a,b from employee | db.sample.employee.find( null, { a: “”, b: “” } ) | employee.query( “”, “{ ‘a’: ‘’, ‘b’: ‘’ }”, “”, “” ) |
select from employee | db.sample.employee.find() | employee.query() |
select from employee where age=20 | db.sample.employee.find( { age: 20 } ) | employee.query( “{ ‘age’: 20 }”, “”, “”, “”) |
select from employee where age=20 order by name | db.sample.employee.find( { age: 20 } ).sort( { name: 1 } ) | employee.query( “{ ‘age’: 20 }”, “”, “{ ‘name’: 1 }”, “” ) |
select from employee where age > 20 and age < 30 | db.sample.employee.find( { age: { $gt: 20, $lt: 30 } } ) | employee.query( “{ ‘age’: { ‘$gt’: 20, ‘$lt’: 30 } }”, “”, “”, “”) |
create index testIndex on employee(name) | db.sample.employee.createIndex( “testIndex”, { name: 1 }, false ) | employee.createIndex( “testIndex”, “{ ‘name’: 1 }”, false, false ) |
select from employee limit 20 offset 10 | db.sample.employee.find().limit( 20 ).skip( 10 ) | employee.query( “”, “”, “”, “”, 10, 20 ) |
select count() from employee where age > 20 | db.sample.employee.find( { age: { $gt: 20 } } ).count() | employee.getCount( “{ ‘age’: { ‘$gt’: 20 } }” ) |
update employee set a=a+2 where b=-1 | db.sample.employee.update( { $inc: { a: 2 } }, { b: -1 } ) | employee.update( “{ ‘b’: -1 }”, “{ ‘$inc’: { ‘a’: 2 } }”, “” ) |
delete from employee where a=1 | db.sample.employee.remove( { a: 1 } ) | employee.delete( “{ ‘a’: 1 }” ) |