I have two tables. Table A look like this. source ID Type_ID Error_info ABC 100 1 country column missing ABC 100 2 conversion factor missing decimals BCA 200 1 error value in height column BCA 200 2 convertion factor should be 0.001 Table B look like this. source ID Type_1_ID Error_info_1 Type_2_ID Error_info…
Tag: sql
DELETE entry that is older than current datetime in MySQL
I have tried the following among various other statements but thought one of these should obviously work but no luck so far. Please tell me what I’m doing wrong. Not getting an error, it’s just not working. DELETE FROM table_name WHERE from < NOW() DELETE FROM table_name WHERE from < ‘…
How do I add specific columns from different tables onto an existing table in postgresql?
I have an original table (TABLE 1): A B C D 1 3 5 7 2 4 6 8 I want to add column F from the table below (Table 2) onto table 1: A F G H 1 29 5 7 2 30 6 8 As well as adding Column J,L and O from the table below (Table 3)
left join on the first appeared row by datetime
If classes ‘Math’ or ‘Biology’ have flag is NULL or = 0, we need to left join with the first appeared (according to the date) classes ‘Literature’ or ‘English Literature’ from the below. If classes ‘Math’ or ‘Biology’ have flag = 1 then w…
Postgres: How do I count occurrences of each enum value when they exist in columns as an array?
I have an enum State which can contain values like CA, NY, etc. If I have a table Users , with a column states that contains an array of State values, so for example {CA, NY} how can I write a query to count the users grouped by each State value? so for {CA, NY} that should count 1 for
How to add a column default?
I created a Postgres DB which contains 5 tables. Then I realized that the column student.student_id lacks a column default to generate an UUID: Knowing that some tables are linked to the student table, how can I add to the function as column default for student_id so that the result will be: Answer Use ALTER …
How to differentiate between no rows and foreign key reference not existing?
My users table contains Alice, Bob and Charles. Alice and Bob have a 3 and 2 fruits respectively. Charles has none. A relationship is established using a foreign key constraint foreign key (user_id) references users (id) and a unique (user_id, name) constraint, allowing zero or one fruit per user. Charles doe…
how do path at the final url like this “~” [closed]
Closed. This question needs details or clarity. It is not currently accepting answers. Want to improve this question? Add details and clarify the problem by editing this post. Closed last month. Improve this question what is code “~” from the end of this url ? udel.edu/~, and what mean ? Answer Ne…
How to update with order in SQL Server?
I am using SQL Server, and I have a table that looks like this: I want to update id to have a sequence of rows ordered by distance asc, then i asc I tried this but I am getting an error Incorrect syntax near “order” How to fix that? Answer You need to use ROW_NUMBER inside a derived table or
How can combine rows of a table with sql?
I have a table like this: Type rank A 1 A 2 B 3 A 4 B 5 B 6 B 7 A 8 And i want convert it to this table with sql query: Type rank A 2 B 3 A 4 B 7 A 8 How can I do this with and with out window functions? Answer It