MySQL basic operation of the increase and deletion check

Inquire

Querying all Columns

SELECT * from table name;
Cases:
SELECT * from Classes;

Querying a specified column

You can use as to specify an alias for a column or table

Select column 1, column 2,... from table name;
Cases:
Select Id,name from Classes;

Increase

Note: The primary key column is autogrow, but requires a placeholder for full column insertion, typically using 0, and the actual data will prevail after the insert succeeds

Full column Insert: The order of values corresponds to the order of the fields in the table

Insert into table name values (...)
Cases:
INSERT into students values (0, ' Guo Jing ', 1, ' Mongolia ', ' 2016-1-2 ');

Partial column insertion: The order of values corresponds to the given column order

Insert into table name (column 1,...) VALUES (value 1,...)
Cases:
INSERT into students (Name,hometown,birthday) VALUES (' Huang Rong ', ' Peach Island ', ' 2016-3-2 ');

The above statement can insert a row of data into a table at a time, and you can insert multiple rows of data at once, which can reduce communication with the database

Full column multiple row inserts: The order of values corresponds to the given column order

Insert into table name values (...), (...) ...;
Cases:
Insert into classes values (0, ' Python1 '), (0, ' python2 ');
Insert into table name (column 1,...) VALUES (value 1,...), (value 1,...) ...;
Cases:
INSERT into students (name) values (' Yang Kang '), (' Yang over '), (' Little Dragon Girl ');

Modify

Update table name set column 1= value 1, column 2= value 2 ... where condition
Cases:
Update students gender=0,hometown= ' tomb ' where id=5;

Delete

Delete from table name where condition
Cases:
Delete from students where id=5;

Tombstone is essentially a modification operation

Update students set isdelete=1 where id=1;

MySQL basic operation of the increase and deletion check