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#Hello World in Three Different Language. 1) IN JAVA public class HelloWorld { public static void main(String[] args) { System.out.println("Hello, World"); } } 2) IN PHP <?php echo 'Hello World';?> 3) IN PYTHON print "Hello World"

Download MongoDB from  https://www.mongodb.com/download-center#community MongoDB connection with PHP(XMPP) for windows 1) Install MongoDB. 2) open cmd with the administrator and where MongoDB is installed. when it is installed in C drive --- 3)type in cmd---C:\Program Files\MongoDB\Server\3.2\bin. 3)Make folder test in d Drive client location C:\Program Files\MongoDB\Server\3.2\bin\mongod --dbpath "d:\test\mongodb data 4) run client open another cmd with the administrator and run the mongo.exe 5) after that download the latest package from- https://s3.amazonaws.com/drivers.mongodb.org/php/index.html 6) then open c--> xampp-->php-->ext-->paste all extracted files. and change one file to 'php_mongo.dll' 7) open php_ini and write---- extension=php_mongo.dll 8) set the environment variable in control panel-->system setting->advnaced->set environment variable--paste the path of PHP and then restart the server and check in php ini file m

Transaction in my SQL is limited to some engines. like InnoDB. it is used basically to control replication and follow the ACID property. There is 2 stage of the transaction -- 1) begin() 2) commit OR rollback All DML which you write in between begin() and rollback/commit, if any operation fails then it will rollback the whole process and transaction which happens else it will commit means process is done. The tables are being locked when we begin and after DML operations it is being unlocked. begin update table name commit or rollback