SQL is a structured query language, used to access over the back end of the data, there are several commands are being used to access over the data. There are two types of structured query language,

• Data definition language
• Data query language

These two automata look more different and give different solutions too. In data definition language, it is created to define the data base. Whereas the dml is created to manipulate means managing data within the database.

Data definition language works for the statements create alter, drop and truncate. Where, the Data manipulation stands for definition of the data after it has been created. Once cannot a table with DML commands, it is possible only with the DDL commands. Update, truncate, select, and insert these commands stands for the DML.

Some of the mostly used sql commands are

• Insert
• Merge
• Update
• Truncate
• Drop

Insert command is used for the purpose of insertion of new data inside the table. Merge command is used to two columns or two rows, it depend on the user choice. Truncate is used to delete the contents in the data but it will not remove the memory space occupied by the variable, but Drop totally remove and free the space, so that other variable can make use of that memory space. Update is simply updating the table details.

Syntax query to create table is, create table- table name (variable, data type (memory space in number)); this is the sample way to create table using Sql commands. The sql commands are widely used by many of them; many do certification courses in oracle do know depth about SQL query and commands.

All over the world people make use of the sql tool, many software companies the back end work process is done with the help of the sql but total manual control is very much complicated, hence it is better to approach the Online SQL Editor . This tool is much helpful to manipulate and change the commands, if any corrections and mistakes found, it will eradicate that and help the back end operator to work with more ease.

It is much important in terms of maintaining the data, all the programs and details are collected and maintained in the server thorough this sql commands. Server maintainer will always use this tool for safe and protection of wrong commands over the system.