I have a table containing measurement information of several tests per devices: device_id gives the information on which device was tested measurement_no is an incrementing number giving the order in which tests has been performed test gives you the name…
EDIT: As requested, our table schema is, posts: postid (primary key), post_text comments: commentid (primary key) , postid (foreign key referencing posts.postid), comment_text replies replyid (primary key) commentid (foreign key referencing comments.commentid) reply_text I have the tables posts, comments, and…
For example, I have a simple table books: author book Author-A Book-A1 Author-A Book-A2 Author-B Book-B1 Author-C Book-C1 Author-C Book-C2 And I need to count books by each author, so I'll write: select author, count(*) from books group by author…
When playing with MySQL I noticed that if I run SELECT * FROM table WHERE !value; returns the same thing as SELECT * FROM table WHERE value IS NOT NULL; The table is "employees" and the column is "MiddleInitial" (strings).…
I have exact two tables but some value differences. So I would like to find those differences with condition that if the column value has a difference of more than 10. For example, all 9 columns have the same values…
I have a table like- id---------rowNum------status aa23 1 HIT aa23 1 HIT aa23 1 HIT aa23 2 MISS aa23 2 MISS aa24 2 MISS aa24 2 MISS So basically I need to get the count of and HIT and MISS…
I have two tables with similar columns and I would like to know the difference between these tables. So if all values (column-wise) of the row exists in both table it is fine (I do not want to see this),…
Assume I have two tables: cameraNum roadNum isWorking 100 1 TRUE 101 1 FALSE 102 1 TRUE 103 3 FALSE 104 3 FALSE 105 7 TRUE 106 7 TRUE 107 7 TRUE 108 9 FALSE 109 9 FALSE 110 9…
If I have TEXT data type (up to 65,535 characters), is taking first 500 characters faster than the whole column? There is a LEFT function that can particularly be used in this situation, but I'm wondering if it improves performance…
I want to join two tables: Table1: Task Hours Client Time Task A 1 Client A 2023-01-01 Task A 2 Client A 2022-03-04 Task A 3 Client A 2023-01-01 Task A 4 Client A 2022-03-04 Task B 5 Client A…