Manipulating Data using DML

Data Manipulation Language :
A DML statement is executed when you :

• Add new rows to a table
• Modify existing rows in a table
• Remove existing rows from a table

• A transaction consists of a collection of DML statements that form a logical unit of work.

INSERT Statement Syntax :
Add new rows to a table by using the INSERT statement :

• INSERT INTO table [(column [, column...])] VALUES (value [, value...])[,(value [,value..])];
  

• With this syntax, only multiple rows are inserted at a time.

Inserting New Rows :

• Insert a new row containing values for each column.
• List values in the default order of the columns in the table.
• Optionally, list the columns in the INSERT clause.
• Enclose character and date values in single quotation marks.
• INSERT INTO dept(deptno, dname, loc) VALUES (50, 'Public Relations',’EDMONTON’);

Inserting Rows with Null Values :
Implicit method :

• Omit the column from the column list.
• INSERT INTO dept (deptno, dname ) VALUES (60, 'Purchasing');

Explicit method :

• Specify the NULL keyword in the VALUES clause.
• INSERT INTO dept VALUES (70, 'Finance', NULL);