Basic Database Operations

Basic knowledge of the database to be used during testing:

1. View the database structure: desc name;

2. Query all columns in the table: SELECT * from name;

3. Select the columns in the query table: choose Sex,name,id from Name;

4. Query a row: SELECT * from name where id= '; (String type Plus ')

5. Use Expression filter criteria query: SELECT * from Shares.app_user where create_time> ' 2017-09-13 ';

6. Fuzzy Search: SELECT * from Shares.app_user where nickname like '% small% ';

7, multiple data, multiple criteria search: SELECT * from Shares.app_user where province in (' Beijing ', ' Henan ');

8, query the table in reverse order: SELECT * from Shares.app_user ORDER BY privilege Desc;

9, the query field is empty data: SELECT * from Shares.app_user where the city was not NULL;

10 Query out the field to find the maximum, minimum, sum: select sum (privilege) from Shares.app_user; (max,min,avg,sum)

Basic Database Operations