MySQL Basic learning-data manipulation

For the operation of the data, there is nothing more than "adding and removing the check" these kinds of operations.

1 increase

The increase in data is inserted using the INSERT statement

Syntax: INSERT into table_name (COLUMN1,COLUMN2,...) VALUES (value1,value2,...)

For example: INSERT into person (name) values (' Lila ');

2 Delete

Delete operation of data, using delete

Syntax: DELETE from table_name WHERE condtion ...

For example: delete from the person where id= ' 1 ';

Note: Delete operation must be conditional, and delete operation must be cautious, accidentally to back pot.

3 update

Data update operation, using the update

Syntax: UPDATE table_name SET column= ' value ' WHERE condition

For example: Update person set name= ' xiaoming ' where id= ' 1 ';

Update statements can also be updated with multiple values

For example: Update person set name= ' xiaoming ', age=12 where id= ' 1 ';

4 Find

Data lookup operations, which are the most frequently used operations, use the Select

Syntax: SELECT column1,column2 from table_name[WHERE condition]

Example: Select name from the person where id= ' 1 '

Common Find operations:

1. Connection Lookup

Use the inner join,left join,right join,out join.

2. Multi-table Lookup

Find more than two tables.

3. Fuzzy Search

Generally use the LIKE keyword and%

4. Nesting lookups

Nested lookups are typically used for conditional filtering lookups.

MySQL Basic learning-data manipulation