Catalog

problem 1：ambiguous

problem 2：Duplicate entry 't07027' for key 'teacher.PRIMARY'

problem 3：mysqldump Command backup problem

problem 1：ambiguous

Column 'S_no' in where clause is ambiguous

 

terms of settlement ：

  WHERE student.S_no Add the table name before the attribute to solve ！

problem 2：Duplicate entry 't07027' for key 'teacher.PRIMARY'

When creating views , Try to add new information , Report errors ！

Duplicate entry 't07027' for key 'teacher.PRIMARY'

 

  terms of settlement ：

Delete the original view , And re create a new view .

Knowledge points supplement ： The view is a virtual table , A table derived from one or more tables in a database

Let's take a look v_teach How views are created ：

CREATE VIEW v_teach AS
SELECT t_no,T_name,major,prof,Department FROM teacher WHERE t_no = 1;

Create the view above SQL We can see clearly in the sentence where t_no = 1; Because a view is a result set of a query statement , So we need to delete this view , Create a new one with the same name (v_teach) The view of .

Change the view as follows ：

CREATE VIEW v_teach AS
SELECT t_no,T_name,major,prof,Department FROM teacher WHERE Department = ' school of computing ';

Now continue to execute the above code

INSERT INTO v_teach VALUES('t07027',' Thank God ',' pedagogy ',' associate professor ',' school of computing ');

Successfully solved ！

 

expand ： In the view , We can see that a message has been inserted , Go back to the table you actually created (teacher) in , We can also see that this message has also been inserted .

 

problem 3：mysqldump Command backup problem

  The use of SQL sentence

mysqldump -u root -p _xscj > D:\ Study \ Backup 

terms of settlement ： 

Enter the correct SQL sentence ：

mysqldump -u root -p _xscj > D:\ Study \ Backup \test.sql

Be careful ： Be sure to add .sql suffix , Otherwise access will be denied ！

 

  Successfully solved ！