I have a postgres database table with nearly 700k records. I would want to have a python script that fetches the records one-by-one at 5seconds interval until the last record. How do I go about it?
Tag: postgresql
Ordering records by an association presence
Lets say I have an instructions table which is associated to a surveys table through survey_instructions join table. What I need to achieve is to fetch all instruction records, but ordered by an …
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How to use IF statement in the PostgreSql (11 version)? I tried just raw IF usage but got problem (syntax error at or near “IF”). To resolve this problem people propose to use ‘do &&’ but it does not work as well (Unterminated dollar quote started at position 3 in SQL DO $$ BEGIN IF ……). Here is my SQL
Count sum of two columns
I am trying to count the sum of 2 columns from a subset of results, so far I have put this together SELECT COUNT(*) FROM table_name WHERE column_1 + column_2 >= 3 IN (SELECT id …
I have a table that contains a set of products purchased and their total quantities. How to get the product having minimum quantity for that month?
I want to extract the products corresponding to each month having minimum and the maximum quantity. That is for month 1 the product having the least quantity that is “Butter” should be displayed along …
How can I seperate one column into multiple columns depending on their value when selecting it?
I have a table called assignment_answers, which has the following attributes: assignment_answers_id, question_id and order. The order is an attribute, which can take a value from 0 to 9. I would like …
How to pass a variable to a subselect in a view
I have a table of posts, post_likes, and I need a query that will give me both totals for likes for posts, and also a given specific user’s likes for those posts. This means I need a good way of …
Changing data type to float and rounding to 2 decimal digits
Tables: Goal: Display each unique job, the total average salary (FLOAT and rounded to 2 decimal places), the total people and the total salary (Float and rounded to 2 decimal places) and order by highest average salary. So the challenge is to keep the cast type as float while rounding it to 2 decimal places. I’ve gotten to where I’ve
How to limit the no of results to just 5 per ‘user’ but allow for more rows if the immediate value at 5th row is same as the consecutive rows?
I have a database with Domain_id, salary and salary date of an organisation. My question is i have to find 5 highest salaries per domain, but the no of rows (5 rows) can increase to more, if the …
Will a transaction see inserts from another concurrent transaction if they are in Repeatable Read isolation level in Postgresql?
If during execution of transaction A, a concurrent transaction B adds a row that fits the search criteria of transaction A and commits, what will happen when transaction A commits? Will it include the …