H2 Database - Select

Select command is used to fetch record data from a table or multiple tables. If we design a select query, then it returns data in the form of result table called result sets.

Syntax

The basic syntax of SELECT statement is as follows −

SELECT [ TOP term ] [ DISTINCT | ALL ] selectExpression [,...] 
FROM tableExpression [,...] [ WHERE expression ] 
[ GROUP BY expression [,...] ] [ HAVING expression ] 
[ { UNION [ ALL ] | MINUS | EXCEPT | INTERSECT } select ] [ ORDER BY order [,...] ] 
[ [ LIMIT expression ] [ OFFSET expression ] [ SAMPLE_SIZE rowCountInt ] ] 
[ FOR UPDATE ]

To fetch all the available fields, use the following syntax.

SELECT * FROM table_name;

Example

Consider the CUSTOMER table having the following records −

+----+----------+-----+-----------+----------+ 
| ID | NAME     | AGE | ADDRESS   | SALARY   | 
+----+----------+-----+-----------+----------+ 
|  1 | Ramesh   |  32 | Ahmedabad |  2000.00 | 
|  2 | Khilan   |  25 | Delhi     |  1500.00 | 
|  3 | kaushik  |  23 | Kota      |  2000.00 | 
|  4 | Chaitap |  25 | Mumbai    |  6500.00 | 
|  5 | Hardik   |  27 | Bhopal    |  8500.00 | 
|  6 | Komal    |  22 | MP        |  4500.00 | 
|  7 | Muffy    |  24 | Indore    | 10000.00 | 
+----+----------+-----+-----------+----------+ 

To get the customer table along with the given data, execute the following queries.

CREATE TABLE CUSTOMER (id number, name varchar(20), age number, address varchar(20), 
salary number);  

INSERT into CUSTOMER values (1,  Ramesh , 32,  Ahmedabad , 2000); 
INSERT into CUSTOMER values (2,  Khilan , 25,  Delhi , 1500); 
INSERT into CUSTOMER values (3,  kaushik , 23,  Kota , 2000); 
INSERT into CUSTOMER values (4,  Chaitap , 25,  Mumbai , 6500); 
INSERT into CUSTOMER values (5,  Hardik , 27,  Bhopal , 8500); 
INSERT into CUSTOMER values (6,  Komal , 22,  MP , 4500); 
INSERT into CUSTOMER values (7,  Muffy , 24,  Indore , 10000);

The following command is an example, which would fetch ID, Name and Salary fields of the customers available in the CUSTOMER table.

SELECT ID, NAME, SALARY FROM CUSTOMERS;

The above command produces the following result.

+----+----------+----------+ 
| ID | NAME     | SALARY   | 
+----+----------+----------+ 
|  1 | Ramesh   |  2000.00 | 
|  2 | Khilan   |  1500.00 | 
|  3 | kaushik  |  2000.00 | 
|  4 | Chaitap |  6500.00 | 
|  5 | Hardik   |  8500.00 | 
|  6 | Komal    |  4500.00 | 
|  7 | Muffy    | 10000.00 | 
+----+----------+----------+ 

Use the following query to fetch all the fields of CUSTOMERS table.

SQL> SELECT * FROM CUSTOMERS;

The above query produces the following result −

+----+----------+-----+-----------+----------+ 
| ID | NAME     | AGE | ADDRESS   | SALARY   | 
+----+----------+-----+-----------+----------+ 
|  1 | Ramesh   |  32 | Ahmedabad |  2000.00 | 
|  2 | Khilan   |  25 | Delhi     |  1500.00 | 
|  3 | kaushik  |  23 | Kota      |  2000.00 | 
|  4 | Chaitap |  25 | Mumbai    |  6500.00 | 
|  5 | Hardik   |  27 | Bhopal    |  8500.00 | 
|  6 | Komal    |  22 | MP        |  4500.00 | 
|  7 | Muffy    |  24 | Indore    | 10000.00 | 
+----+----------+-----+-----------+----------+