PostgreSQL INSERT INTO Keyword

The PostgreSQL INSERT INTO keyword is used to insert a new record in a table. There are two ways of using INSERT INTO keyword which are mentioned below.

Syntax

The below syntax specifies column names and respective values to be inserted.

INSERT INTO table_name (column1, column2, column3, ...)
VALUES (value1, value2, value3, ...);

The below syntax specifies values only. Therefore, it is essential to specify values in the same order as the columns in the table.

INSERT INTO table_name 
VALUES (value1, value2, value3, ...);

Example:

Consider a database containing a table called Employee with the following records:

• To insert a new record in the Employee table, the query is:

  INSERT INTO Employee (EmpID, Name, City, Age, Salary)
  VALUES (7, 'Suresh', 'Mumbai', 29, 2900);
  INSERT INTO Employee 
  VALUES (8, 'Zayne', 'Oslo', 31, 3400);
  
  -- see the result
  SELECT * from Employee
  

  
  

  Now the Employee table will contain following records:

  EmpID	Name	City	Age	Salary
  1	John	London	25	3000
  2	Marry	New York	24	2750
  3	Jo	Paris	27	2800
  4	Kim	Amsterdam	30	3100
  5	Ramesh	New Delhi	28	3000
  6	Huang	Beijing	28	2800
  7	Suresh	Mumbai	29	2900
  8	Zayne	Oslo	31	3400

• Insert Data Only in Specified Columns: To insert data in specified columns, it is necessary to specify column names. See the example below:

  INSERT INTO Employee (EmpID, Name, Age)
  VALUES (7, 'Suresh', 29);
  
  -- see the result
  SELECT * from Employee
  

  
  

  Now the Employee table will contain following records:

  EmpID	Name	City	Age	Salary
  1	John	London	25	3000
  2	Marry	New York	24	2750
  3	Jo	Paris	27	2800
  4	Kim	Amsterdam	30	3100
  5	Ramesh	New Delhi	28	3000
  6	Huang	Beijing	28	2800
  7	Suresh		29

Populate one table using another table

A table can be populated using another table by using INSERT INTO SELECT keyword. Please note that the other table should have the set of fields which are required to populate in the first table.

Syntax

The syntax for using INSERT INTO SELECT keyword in PostgreSQL is given below:

INSERT INTO table1 [(column1, column2, ...)] 
SELECT column1, column2, ...  FROM table2
[WHERE condition];

Example:

Consider a database containing tables called Employee and HREmployee with the following records:

Table 1: Employee table

Table 2: HREmployee table

The HREmployee table contains no records and have following fields - HRID, Name and Address.

• The given fields of HREmployee table can be populated using Employee table by using below query:

  INSERT INTO HREmployee (HRID, Name, Address)
  SELECT EmpID, Name, City FROM Employee
  WHERE EmpID IN (1, 4, 5);
  
  -- see the result
  SELECT * from HREmployee
  

  
  

  Now the HREmployee table will contain following records:

  HRID	Name	Address
  1	John	London
  4	Kim	Amsterdam
  5	Ramesh	New Delhi