Description
The SELECT proclamation is utilized to retrieve the information from the database. SQL Select statement writes the query and returns the result as a result set. In select statement the Where Clause clause will work like below:
- If the condition is true then the row is incorporated into the outcome.
- On the off chance that the condition is false then the line is excluded in result.
- If the column being mentioned in the condition is NULL the also then row will not be included in the result.
Conceptual
figure
Syntax
The syntax for SQL Select statement is as follows:
SELECT[ALL|DISTINCT] column1, column2.....FROM <table_name>,..... WHERE <search_condition>;
WHERE => Used to mention a search condition to obtain the desired result set and limits the number of rows.
ALL or DISTINCT => For retrieving all record and eliminate duplicate records respectively.
Type-1
To fetch all the record from table department, use following query:
[c]
sql> create table department(dept_id int,dname varchar(255),commission int)
Query ok, 0 rows affected (0.64 sec)
sql> insert into department values(1001,'Oracle',12000);
Query OK, 1 row affected (0.10 sec)
sql> insert into department values(1002,'Mysql',Null);
Query OK, 1 row affected (0.39 sec)
sql> select * from department;
+---------+--------+------------+
| dept_id | dname | commission |
+---------+--------+------------+
| 1001 | Oracle | 12000 |
| 1002 | Mysql | Null |
+---------+--------+------------+
2 rows in set (0.00 sec)
sql>SELECT * FROM department WHERE commission='Null';
+---------+--------+------------+
| dept_id | dname | commission |
+---------+--------+------------+
| 1002 | Mysql | Null |
+---------+--------+------------+
1 rows in set (0.00 sec)
[/c]
Here in the above example,select statement is used to retrieve all the field values from the database table department.
Key Points
- SQL Select proclamation - Select proclamation is utilized to recover the records from the database.