Inserting data into a existing table:
Syntax without column names specified:
INSERT INTO table_name VALUES ('value1','value2');Example:
In the example we have inserted the data in a customer_table where we have 4 columns with name cust_id, first_name, last_name, age and we have inserted the data in the columns with this command.
Syntax without column names specified:
INSERT INTO table_name ('column1','column2') VALUES ('value1','value2');Example:
In this example we have inserted the data in three columns excluding the last_name column, by doing this it will store the information in all the columns and will show NULL in the last_name.
Inserting data in multiple rows:
- To ‘SELECT’ a statement in a table:
Select column_name from table_name;Following command will show the data stored in the column_name column in the database.
- To use ‘WHERE’ command in a table:
Select column_name from table_name Where (column_name = condition);For example:
We have a table with Customers name , age and email given and we need to see only the data of customer whose age is greater than 25.
Select * from customer_table where age>25;This command will show the data of the customers whose age is greater than 25.
- To use logical operators in the query:
Select column_name from table_name Where (column_name = condition) AND (column_name = condition) OR (column_name = condition);- To update data in the table:
UPDATE table_name SET column_name='abc' WHERE condition(column);For example to update the last name of a customer:
UPDATE customer_table SET Last_name='John' WHERE cust_id=5