• SQL to SequoiaDB shell to C++

    SQL to SequoiaDB shell to C++

    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 C++ 驱动程序语法之间的对照。

    SQLSequoiaDB shellC++ Driver
    insert into bar( a, b ) values( 1, -1 )db.foo.bar.insert( { a: 1, b: -1 } )sdbCollection collection ; BSONObj obj = BSON( "a" << 1 << "b" << -1 ) ; collection.insert( obj ) ;
    select a,b from bardb.foo.bar.find( null, { a: "", b: "" } )sdbCollection collection ; sdbCursor cursor ; BSONObj selected ; BSONObj obj ; selected = BSON( "a"<<""<<"b"<<"" ) ; collection .query( cursor, obj, selected ) ;
    select from bardb.foo.bar.find()sdbCollection collection ; sdbCursor cursor ; collection.query ( cursor ) ;
    select from bar where age=20db.foo.bar.find( { age: 20 } )sdbCollection collection ; sdbCursor cursor ; BSONObj condition ; condition = BSON( "age" << 20 ) ; collection .query ( cursor, condition ) ;
    select from bar where age=20 order by namedb.foo.bar.find( { age: 20 } ).sort( { name: 1 } )sdbCollection collection ; sdbCursor cursor ; BSONObj obj ; BSONObj condition ; BSONObj orderBy ; condition = BSON( "age"<<20 ) ; orderBy = BSON( "name"<<1 ) ; collection.query( cursor, condition, obj, orderBy, obj ) ;
    select from bar where age > 20 and age < 30db.foo.bar.find( { age: { $gt: 20, $lt: 30 } } )sdbCollection collection ; sdbCursor cursor ; BSONObj condition ; condition = BSON( "age" << BSON( "$gt" << 20 << "$lt" << 30 ) ) ; collection.query( cursor, condition ) ;
    create index testIndex on bar( name )db.foo.bar.createIndex( "testIndex", { name: 1 }, false )sdbCollection collection ; BSONObj obj ; obj = BSON( "name"<<1 ) ; collection.createIndex ( obj, "testIndex", FALSE, FALSE );
    select from bar limit 20 offset 10db.foo.bar.find().limit( 20 ).skip( 10 )sdbCollection collection ; BSONObj obj ; sdbCursor cursor ; collection .query( cursor,obj, obj, obj, obj, 10, 20 ) ;
    select count() from bar where age > 20db.foo.bar.find( { age: { $gt: 20 } } ).count()sdbCollection collection ; SINT64 count = 0 ; BSONObj condition ; condition = BSON( "age" << BSON( "$gt" << 20 ) ) ; collection.getCount( count, condition ) ;
    update bar set a=2 where b=-1db.foo.bar.update( { $set: { a: 2 } }, { b: -1 } )sdbCollection collection ; BSONObj condition = BSON( "b"<<-1 ) ; BSONObj rule = BSON( "$set" << BSON( "a" << 2 ) ); BSONObj obj ; collection.update ( rule, condition, obj ) ;
    delete from bar where a=1db.foo.bar.remove( { a: 1 } )sdbCollection collection ; BSONObj condition = BSON( "a"<<1 ) ; collection.del ( condition ) ;