SQL statement data operations

I. insert statements

Insert is used to input data into the table. The syntax structure is as follows.

Insert into table name VALUES (value 1, value 2,...) We can also specify the columns to INSERT data:

Insert into table_name (column 1, column 2,...) VALUES (value 1, value 2,...) Example:
Copy codeThe Code is as follows:
Insert into country values ('u.s ')

Ii. update statement

The update statement is used to update data in a table. Its syntax structure is as follows.

UPDATE table name SET column name = new value WHERE column name = A value example:
Copy codeThe Code is as follows:
Update country set countryname = 'China' where countryid = 4

Iii. delete statement

The delete statement is used to delete data in a table. Its syntax structure is as follows.

Example of delete from table name WHERE column name = value:
Copy codeThe Code is as follows:
Delete from country where countryid = 4