Daily Study Notes (12)

1. Compile openfetion0 in the source code, install the required dependent libraries 1, install cmake, and build later than version 2.8 2. Create a build directory 3 under the openfetion directory, cmake-dcmake_install_prefix =/usr-dcmake_build_type = debug4. Go to the build directory to compile: Make installation: Make install5. If openfetion: Error while loading shared libraries: libofetion occurs after installation. so.0: cannot open shared object file: no such file or directory run ldconfig on the terminal

2. MongoDB Quick Start

1. Create the database storage directory/data/DB2 and go to the bin directory ,. /mongod start Server 3 ,. /Mongo start the shell window, here for preliminary study 4, shell is connected to the 'test' database by default, you can "use mydb" switch to mydb database MongoDB and will not create a database for you immediately, it is not created until the data is inserted on the first day. This "delayed creation" method provides better performance. This also means that if no data is inserted, "Show DBs" cannot be used to see empty databases. 5. Insert data to the database in the collection. foo. save ({name: "phinecos"}); dB. foo. find (); we do not need to define a set in advance. MongoDB will be automatically created when the first data is inserted. The stored documents can be of any structure, this means that the Database Upgrade and migration are simple. The above find () actually returns an iterator, VAR cursor = dB. foo. find (); While (cursor. hasnext () printjson (cursor. next (); you can also: DB. foo. find (). foreach (printjson); you can also think of the iterator as an array: printjson (cursor [3]); or simply convert it into an array: var arr = dB. foo. find (). toarray (); 6, query DB. foo. find ({Name: 'phinecos '}). foreach (printjson); it can be seen that the query condition itself is a document in the form of {A: A, B: B ,...} where a = A and B = B and... ". this query is equivalent to "select * From Foo where name = 'phinecos '". You can also query Only some fields of the document are returned for the query: DB. foo. find ({X: 4}, {J: true }). foreach (printjson); this will only display the Field J, which is equivalent to "select J From Foo where x = 4" DB. foo. findone ({Name: 'phinecos '}); in this way, only one document can be returned, and the limit method can be used to limit the number of returned results: DB. foo. find (). limit (3); 7, connection string MongoDB: // phinecos: 123 @ localhost/test connect to the local test using the username phinecos and password 123, the MongoDB server creates a thread for each TCP connection. Therefore, it is strongly recommended to use some form of connection pool in applications.

Author: Dongting sangren

Source: http://phinecos.cnblogs.com/

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