Database base types and additions and deletions

Data type:

Integer type: bigint, int, smallint, mediumint, tinyint

Decimal type: decimal, numeric

Float type: Real, float, double

Bit type: bit

Character type: char, varchar, LongVarChar, longtext

Unicode character type: nchar, nvarchar

Textual: Text, Tinytext

Binary type: binary, varbinary

DateTime type: Date, time, DateTime, timestamp, year

The Datetime range is: 1753.1.1--9999.12.31

smalldatetime range is: 1900.1.1--2079.6.6

Create a database: Right-click the database, create a new database, enter a name for the database

Create with a statement

Create DATABASE Fruitgo

Create a table with a database, add column names to the table

Use fruitgocreate table fruit (Code int,name varchar (a), Price decimal (18,2), Chandi varchar (50))

Add data to the table and query the table:

Insert into fruit values (1, ' Apple ', 2.5, ' Yiyuan ') insert into fruit values (2, ' bananas ', 3.5, ' Hainan ') insert into fruit values (3, ' pear ', 2.5, ' Yantai ') insert into fruit values (4, ' grapes ', 4.5, ' Zhejiang ') insert into fruit values (5, ' Mango ', 5.5, ' Guangdong ') select * from fruit

Delete and change the data:

Query data:

SELECT * FROM fruit--query all select name from fruit--query a column select Name,chandi from fruit--query multiple columns, separated by commas select * FROM fruit where co de=4--query an entire row, condition query select name from fruit where code=2--query number 2 for the name of the fruit select Name,chandi from fruit where code=3-- Search for the name and origin of the fruit with number 3

Add Data:

Insert into fruit values (6, ' lychee ', 6.5, ' Hunan ') insert into fruit (code,name,price) VALUES (7, ' pineapple ', 6)

To modify the data:

Update fruit set price=5 where code=4--the price of the fruit numbered 4 is changed to 5update fruit set chandi= ' Nanjing ' where code=5--will be the origin of the fruit with number 5 changed to Nanjing

Delete data:

Delete from fruit--all delete delete from fruit where name= ' pear '--delete entire row of data named Pear

Database base types and additions and deletions