What I’m trying to do is build a table of unique sets of rows. What is the aim? I’m building an app for a service provider (let’s say cable company for example). Every customer has a set of …
Tag: database
How to change query result into another value in MYSQL?
For example, I have a column named ‘form_type’ consisted of int (1-4) id_event|form_type ——–|———- 001 |1 001 |3 001 |4 002 |2 002 |1 When i query SELECT form_type …
SQL statement to update rows in a table, insert into/update same table
I have a seemingly pretty simple situation here, but one which I have never dealt with. I have researched the issue and have found situations pretty similar, but not close enough to run on a production db. I have 1 table with 2 columns. I want to find all entries that share the same values in column 1, and up…
Seperate tables with same attributes in SQL
When using SQL database, when I have tables with same attributes. For example if I have [posts] with attributes (id, image, description, number of likes and dislikes) [Comments] with attributes (id, image, description, number of likes and dislikes) and [Replies] with attributes (id, image, description, number…
Count of line item in MySQL
I have a complex query joined to multiple tables to show a “transaction history”, I want a quick and easy way to count the occurrences of order_id to make it as the line_number. I had it done with code but for performance reason I want to have it done with MySQL. Here is an example of what I have:…
How to JOIN postmeta table and get the posts before the date of custom field using SQL
I’d like to combine wp_posts table and wp_postmeta table and get the posts before the date of custom field. Code with only wp_posts table is below and it works fine I want to add “postmeta table” to “post table” and get only posts before the date of custom field if it is “W…
Postgresql Select and display one column based on another column
WALLET TABLE ID IS_SPEND HOWMUCH true. 500 false. 1000 true. 5 I want to calculate how much money I have after several transactions. spend as spend money and not spend as earn money I tried But it cannot reach my goal. I don’t know how can I get the result I want, just output 495 is perfect. Answer You …
SQL select the latest record on joined tables
I want to retrieve the property which an user paid a tax last. have two tables person_properties and property_taxes What I tried so far: This gives me the person_id along the max year. But I actually need the property_id, the property which an user paid last. If I replace pp.person_id by pp.property_id, I the…
How to make this Query without using UNION?
I am not very good at making query’s. So could someone explain and help me with this query? I need to inner join 2 tables ‘Slaap’ And ‘Eten’. i need all ‘eten’ where ID = 5 and i need all ‘Slaap’ where ID = 5. I could only achieve this with a UNION but tha…
Can’t delete records from the same table using NOT EXISTS MySQL syntax
I want to perform deletion in the same table. I’ve tried different ways, but I still can’t get it right. So, I got this error You can’t specify target table ‘tb’ for update in FROM clause. I tried aliasing the tables, but nothing done. I can’t figure out what is missing. I …