PostgreSQL has SETOF <sometype> type according to the doc and SETOF <sometype> type is used in a function as shown below: -- ↓ ↓ ↓ Here ↓ ↓ ↓ CREATE FUNCTION my_func() RETURNS SETOF <sometype> ... Now, I want to…
I'm fairly new to SQL and have an exercise I'm trying to figure out how to translate a YEAR column into the following conditions: YEAR is 1 if student is registered in courses 1009 & 1029 YEAR is 2 if…
My question is that how many times will COUNT(*) be called for each group? Three times or just one time? If the answer is three times, how can i optimize it. SELECT COUNT(*) AS num1, COUNT(*) / 10 AS num2,…
I need to fetch the string For reference 110_112_120_122_130_132_140_143_149_151_154_160_162_165_171_173_194_215_236_257_278_299 use this as a subjects I am using the below query select * from table_name where subjects like '%_21_%' ; which is not showing desired result. Note - 21 can come…
I used to work with Oracle, where after creation of a new database user you need to grant them a few privileges, ex. to connect(CREATE SESSION) to the database or create a table(CREATE TABLE). Otherwise the user is useless and…
I need to update a specific value in a column with the json type. All solutions I found online are either for jsonb or don't seem quite right and give me an syntax error and I don't know why. That…
I recently started learning postgresql, and I had a little problem setting up relationships between tables. I have 2 tables - users and projects. Each project has its creator (user), and each user has an array with his projects. create…
I am trying to get distinct values from each column and not distinct row values. My Query is: SELECT DISTINCT ac.admin_id , sc.student_id , tc.teacher_id from contact c join admin_contacts ac on ac.`contact_id` = c.id join student_contacts sc on sc.`contact_id`=…
I have a table structure as follows: Shops Table: id shop_name 1 My Shop 2 Another Shop 3 Final Shop Orders Table: shop_id order_id data created_at 1 123 json 01/01/2023 2 456 json 01/01/2023 3 234 json 02/02/2023 1 765…
class Marriage(BaseModel): users = ArrayField(BigIntegerField) chat_id = BigIntegerField() class Meta: indexes = ( (('users', "chat_id"), True), ) I would like to make a unique index for both user values and chat_id for example: there is already such a row in…