Using INSERT SQL command

Data Manipulation Language (DML) statements are used for managing data in database. DML commands are not auto-committed. It means changes made by DML command are not permanent to database, it can be rolled back.

Talking about the Insert command, whenever we post a Tweet on Twitter, the text is stored in some table, and as we post a new tweet, a new record gets inserted in that table.


INSERT command

Insert command is used to insert data into a table. Following is its general syntax,

INSERT INTO table_name VALUES(data1, data2, ...)

Lets see an example,

Consider a table student with the following fields.

s_idnameage
INSERT INTO student VALUES(101, 'Adam', 15);

The above command will insert a new record into student table.

s_idnameage
101Adam15

Insert value into only specific columns

We can use the INSERT command to insert values for only some specific columns of a row. We can specify the column names along with the values to be inserted like this,

INSERT INTO student(id, name) values(102, 'Alex');

The above SQL query will only insert id and name values in the newly inserted record.


Insert NULL value to a column

Both the statements below will insert NULL value into age column of the student table.

INSERT INTO student(id, name) values(102, 'Alex');

Or,

INSERT INTO Student VALUES(102,'Alex', null);

The above command will insert only two column values and the other column is set to null.

S_idS_Nameage
101Adam15
102Alex

Insert Default value to a column

INSERT INTO Student VALUES(103,'Chris', default)
S_idS_Nameage
101Adam15
102Alex
103chris14

Suppose the column age in our tabel has a default value of 14.

Also, if you run the below query, it will insert default value into the age column, whatever the default value may be.

INSERT INTO Student VALUES(103,'Chris')