Shulou(Shulou.com)06/01 Report--

* * query class *

Use library name-enter the library and use the

Show databases;-query all library names

Select*from Table name-finds all items with the specified table name

Desc table name;-query all column names of the table

Show tables;-query all tables

* * end of query class *

* * create or delete database classes *

Create database database name default charset='utf8';-build a database

Dorp database database name;-Delete a database

Delete table name;-Delete a table

Alter table table name drop column name-deletes a column name from the specified table

Alter table table name add column name type (e.g. varchar) set the number of digits [(e.g. 10)] set properties (such as primary key)-add a column name to the specified table-

* * end of building or deleting database classes *

* * start setting property sheet *

* *

* U: unique (Unique) P: primary key (Primary key) N: non-empty (Not Null) C: (check) *

* *

* D: (add a value after Default) F: (foreign key) (text: choose CHAR or VARCHAR) *

* * set the end of the property sheet *

-- start to build the table--

Create table table name (

Column name (self-defined) type (text type: varchar) [set number of digits (set by yourself)] [set setting properties ()]

Column name (self-defined) type (integer type: int) [set number of digits (set by yourself)] [set property ()]

Column name (self-defined) type (integer type: tinyint) [set number of digits (set by yourself)] [set property ()]

Column name (self-defined) type (decimal type: float) [set number of digits (set by yourself)] [set property ()]

Column name (self-defined) type (decimal type: double) [set number of digits (set by yourself)] [set property ()]

Column name (self-defined) type (decimal type: declmal (mfocus n) [set number of digits (set by yourself)] [set property ()]

-Special

-m represents the number of digits of this number

-n indicates how many places there are after the decimal point.

Column name (self-defined) type (string type char (m)) [set number of digits (set by yourself)] [set property ()]

-m indicates how many characters you set the length, up to 255 characters.

Column name (self-defined) type (string type varchar (m)) [set number of digits (set by yourself)] [set property ()]

-- m indicates that there is no limit to how many characters you set the length.

Column name (self-defined) type (date type date) [set date (set by yourself, such as 1000-1-1)] [set property ()]

Column name (self-defined) type (time type time) [set time (such as 00:00:00)] [set property ()]

Column name (self-defined) type (date-time type datetime) [set date-time (set by yourself, for example, 100,100,100: 00:00)]

[set properties ()]

)

-- end of table creation--

*

* assign values to the columns in the table *

* *

* insert into table name (column name 1, column 2, column name 3.) values (column name 1 value, column name 2 value, column name 3 value,...); *

* *

* Insert into table name values (column name 1 value, column name 2 value, column name 3 value);

* *

* the values of all the column names of this table must be written in the following values *

*

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