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PostgreSQL Tutorial PostgreSQL Advanced PostgreSQL Database Account Management PostgreSQL References

PostgreSQL FROM Keyword



The PostgreSQL FROM keyword is used to specify the table from which the data should be selected or deleted.

Example:

Consider a database table called Employee with the following records:

EmpIDNameCityAgeSalary
1JohnLondon253000
2MarryNew York242750
3JoParis272800
4KimAmsterdam303100
5RameshNew Delhi283000
6HuangBeijing282800

  • To select the Name and Salary data of the employees present in the Employee table, the following query can be used:

    SELECT Name, Salary FROM Employee;
    

    This will produce the result as shown below:

    NameSalary
    John3000
    Marry2750
    Jo2800
    Kim3100
    Ramesh3000
    Huang2800
  • To select all fields of the Employee table, the query will be:

    SELECT * FROM Employee;
    

    This result of the following code will be:

    EmpIDNameCityAgeSalary
    1JohnLondon253000
    2MarryNew York242750
    3JoParis272800
    4KimAmsterdam303100
    5RameshNew Delhi283000
    6HuangBeijing282800
  • To delete the records of an employee whose EmpID is 5, the query will be:

    DELETE FROM Employee
    WHERE EmpID = 5;
    
    --See the result
    SELECT * FROM Employee
    

    Now the Employee table will contain following records:

    EmpIDNameCityAgeSalary
    1JohnLondon253000
    2MarryNew York242750
    3JoParis272800
    4KimAmsterdam303100
    6HuangBeijing282800
  • Similarly, to delete the records of an employee where city starts with 'New', the query will be:

    DELETE FROM Employee
    WHERE City LIKE 'New%';
    
    -- see the result
    SELECT * from Employee;
    

    Now the Employee table will contain following records:

    EmpIDNameCityAgeSalary
    1JohnLondon253000
    3JoParis272800
    4KimAmsterdam303100
    6HuangBeijing282800

❮ PostgreSQL Keywords