Common operations for Databases in Linux

1-Connect to the database:

- - -P

 xxxxx @xxx : ~  $ mysql - h localhost - u jiangbiao -  penter password:welcome  to  the  MySQL Monitor. Commands end  with ; or   \g.your MySQL Connection ID  is  2444832  server version:  5.5 . 40  - log  Source Distribution 

2-Display the table information, including the engine used, for mysql , only the InnoDB engine supports trigger actions

CREATE TABLE tbl_buniness;

3-Display the database :

show databases;

4-Using the database:

 use DatabaseName;

5-Show data table:

Show tables;

6-Show the specific table structure:

Describe TableName;

7-Insert Operation:

INSERT  into' Root_trigger ' (' id ', ' data ')VALUES('1','test root Line 1'),         ('2','test root Line 2'),         ('3','test root Line 3');

8- DELETE CASCADE Handle the Cascade delete operation through the processing mechanism of the FOREIGN KEY constraint:

--Create a Test main table. ID is the primary key.CREATE TABLETest_main (IDINT    not NULL, ValueVARCHAR(Ten),  PRIMARY KEY(ID)); --Create a Test sub-table.CREATE TABLEtest_sub (IDINT   not NULL, main_idINT, ValueVARCHAR(Ten),  PRIMARY KEY(ID)); --Insert test Master table data.INSERT  intoTest_main (ID, value)VALUES(1,' One');INSERT  intoTest_main (ID, value)VALUES(2,' Both'); --Insert Test sub-table data.INSERT  intoTest_sub (ID, main_id, value)VALUES(1,1,'Oneone');INSERT  intoTest_sub (ID, main_id, value)VALUES(2,2,'Twotwo');-----Handle by the processing mechanism of the DELETE CASCADE foreign KEY constraintMysql> ALTER TABLEtest_sub -   ADD CONSTRAINTmain_id_cons -   FOREIGN KEY(main_id) -   REFERENCESTest_main (ID) -    on DELETE CASCADE//Query OK,2Rows Affected (0.16sec) Records:2Duplicates:0Warnings:0MySQL> DELETE  from     -Test_main - WHERE     -Id= 1;  - //Query OK,1Row affected (0.02sec) MySQL> SELECT     -   *     -  from     -test_sub;  - //+----+---------+--------+|Id|main_id|Value|+----+---------+--------+|  2 |       2 |Twotwo|+----+---------+--------+1Rowinch Set(0.00Sec

9-If you want to use a trigger to handle, here is an example:

--Create a Test main table. ID is the primary key.CREATE TABLET_test_main (IDINT    not NULL, ValueVARCHAR(Ten),  PRIMARY KEY(ID)); --Create a Test sub-table.CREATE TABLEt_test_sub (IDINT   not NULL, main_idINT, ValueVARCHAR(Ten),  PRIMARY KEY(ID)); --Insert test Master table data.INSERT  intoT_test_main (ID, value)VALUES(1,' One');INSERT  intoT_test_main (ID, value)VALUES(2,' Both'); --Insert Test sub-table data.INSERT  intoT_test_sub (ID, main_id, value)VALUES(1,1,'Oneone');INSERT  intoT_test_sub (ID, main_id, value)VALUES(2,2,'Twotwo'); DELIMITER// CREATE TRIGGERTr_t_test_main_del beforeDELETE  onT_test_main forEach ROWBEGIN  DELETE  fromT_test_subWHEREmain_id=old.id;END;//DELIMITER; MySQL> Delete  fromT_test_mainwhereId= 1; Query OK,1Row affected (0.01sec) MySQL> Select *  fromt_test_sub;+----+---------+--------+|Id|main_id|Value|+----+---------+--------+|  2 |       2 |Twotwo|+----+---------+--------+1Rowinch Set(0.00Sec

  about 8, 92 points  Original link: https://zhidao.baidu.com/question/562372469.html

10-Other:
Here is a blog link that has been organized

Common operations for Databases in Linux