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Syntax:
iNSERT iNTO Table_Name (column_name1, column_name2, column_ name3 ....)
VALUES (‘VALUE1’, ‘VALUE2’, ‘VALUE3’);
Example:
iNSERT iNTO EmpLOyEE_DETAiLS (Emp_NAmE, Emp_DEpARTmENT, Emp_DESiGNATiON,
DATE_OF_BiRTH, ADDRESS)
VALUES (‘SOmNATH_pATRA’, ‘ACADEmiCS’, ‘COmpUTER TEACHER’, ‘2005-05-05’, ‘RANCHi’);
1.4.7 Select
This command is used to display all the results of table.
Syntax:
SELECT * FROm Table_Name;
Example
SELECT * FROm EmpLOyEE_DETAiLS;
Output:
+---------------+----------------+------------------+---------------+---------+
| Emp_NAmE | Emp_DEpARTmENT | Emp_DESiGNATiON | DATE_OF_BiRTH | ADDRESS |
+---------------+----------------+------------------+---------------+---------+
| SOmNATH_pATRA | ACADEmiCS | COmpUTER TEACHER | 2005-05-05 | RANCHi |
+---------------+----------------+------------------+---------------+---------+
Sometimes only a portion of the string needs to match. String pattern matching is what this is known as. For indicating
varying character counts, the ‘LIKE’ keyword can be used in conjunction with two additional reserved characters:
% (for percent) and _(for underscore). A single character is replaced by _, whereas zero or more random characters
are replaced by %.
For example, the following command is used to retrieve the records of all employees whose names begin with the
letter “N”:
SELECT * FROm EmpLOyEE_DETAiLS
WHERE Emp_NAmE LiKE “N%”;
1.5 DataBase constRaints
For smooth functioning, SQL allows us to impose numerous constraints on a table at the time of its creation. Let us learn
about some constraints.
1.5.1 NOT NULL Constraints
The NOT NULL constraint enforces that a column in a table may not allow NULL values, which means that the column
must contain a value. For example, if we want the Roll_No column of the STUDENT table not to be NULL, the NOT NULL
constraint can be used.
CREATE TABLE STUDENT
(
Roll_No iNTEGER NOT NULL,
Name VARCHAR(30),
Gender CHAR(1),
Date_of_Birth DATE,
Database Concepts—RDBMS Tool 169

