Database creation
CREATE DATABASE DATENBANKNAME; // Create a new database, DatenbankName is the library name.
Query database command
Show databases; // Query existing databases to prevent heavy names.
Open the database
Use datenbankname; // Open the database name to DatenbankName.
Delete database
DROP DATABASE DATENBANKNAME; / / Delete Database Name Name DatenbankName
Create a data sheet
Create Table Table_name
Column_name1 Type [Modifiers],
Column_name2 Type [MODIFIERS], ...
);
The // Column column is a single unit of a row of databases in the table.
NOT NULL modifiers indicate that the column cannot contain any NULL values, simply saying that it cannot be empty.
Exception: If the column is defined as Auto_InCrement, the null value will result in an automatically generated value.
The default value is specified for columns.
Delete data table
DROP TABLE TABLE_NAME;
Insert data
INSERT INTO TABLE_NAME (Column1, Column2, ... Columnn)
Values (Value1, Value2, ... Valuen)
Non-standard
INSERT INTO BOOK SET TITLE = 'The Vampire Lestan', Author = 'AnRe Rice';
INSERT INTO FOODS (Name, FAT)
SELECT FOOD_NAME, FAT_GRAMS from Recipes
Plunate the new table by using the data in some other tables (or a set of tables) to insert data.
In this line of grammar, the ORDER BY modifier cannot be included, nor can I choose from INSERT in the table.
delete
Delete from table_name [where clause]
Delete Table1, Table2, ..., Tablen
From Table1, Table2, ..., Tablen
[WHERE CLAUSE]
Inquire
SELECT Colum1, Colum2, ..., Column
From Table1, Table2, ..., Tablen
[WHERE CLAUSE]
Database ()
Returns the name of the current database.
/
Example details
Open the MySQL window
Password input password
If there is no database, new: Here we create a "Datenbank" database
> CREATE DATABASE DATENBANK;
Turn on the database
> Use Datenbank
The newly built data is empty, so the data sheet is to be built, and the name is called UserInfo.
> CREATE TABLE Userinfo
> ID INT (10) Unsigned Auto_INCREMENT NOT NULL, / / Generally, the primary key is used, and each data table is preferably one ID, and automatically assigns. Theunsigned is not negative.
> username varchar (50) Not null, // User name, type VARCHAR, character type, when stored bytes can't exceed 225, and it is taking characters to a few characters, do not automatically.
> Password varchar (50) Not null, //
> Info Blob, / / You can put some big text content.
> JOINDATE VARCHAR (50), // The time stored here, you can use characters, or time type, such as DateTime
> Primary Key (ID)); // Never miss the setting primary key
> ALTER TABLE UserInfo Add text blob; // Add a new field. But in MySQL, you can change a field.
> INSERT INTO UserInfo (Username, Password, Info, Joindate VALUES ('GSSQTN', 'GSSQTN', 'Info', Now ()); // Character type is necessary to add quotation marks, otherwise it will be wrong. this is Insert a new record.> Update UserInfo Set UserName = 'arlene' where id = 1; // Modify the original record, if not, turn the content UserName in the current data table to Arlene.
> delete from userinfo; // Delete content in the data table, if you do not add, completely delete
> delete from userinfo where id = 1; // Delete ID = 1 record
> Select * from userinfo; // View data sheet record, plus conditions can specify a record that meets the eligibility.
> Select * from userinfo order by id; // View data table record, and sorted according to ID, this is small to big. If you want to view, you can add DESC
> Select * from userinfo Oder BY ID LIMIT 0, 10; // View Data Table Record, and sorted by ID and display the previous ten records .limit is the meaning of the limit.
> show tables; / / View the open database has any data table.
> DROP TABLE UserInfo; // Delete Data Sheet UserInfo
