Inserting and selecting data

Adding data:

• INSERT INTO table VALUES (value1, value2, ...); gives a value for every column, in order.
• INSERT INTO table (column1, column2) VALUES (value1, value2); fills only the named columns.

Text and dates go inside single quotes: 'Atharv', '2025-04-12'. Records must be inserted into a referenced table (such as GUARDIAN) before the table that refers to it (STUDENT), or the foreign key will have nothing to point to.

Asking questions: the SELECT statement retrieves data:

SELECT column1, column2 FROM table WHERE condition;

• SELECT * FROM table; shows all the columns.
• AS gives a column a new name in the output only; the table itself does not change. For example, SELECT Ename, Salary * 12 AS 'Annual Income' FROM EMPLOYEE;
• DISTINCT removes repeated values from the output: SELECT DISTINCT DeptId FROM EMPLOYEE; lists each department just once.
• WHERE picks out rows that meet a condition, using comparison operators (=, <, >, <=, >=, != or <>) and logical operators (AND, OR, NOT).