I have the following dataset in a postgresql table called testtable in testdb. I have accidentally copied over the database and duplicated rows. How can I delete the duplicates? Row 1 and row 5 are copies in this frame and row 2 and row 4 are copies too. I have never used sql before to drop duplicates I have …
Tag: sql-delete
About “group function is not allowed here”
I have a table with job, salary and date columns. I am writing the following query in PL/SQL, but I am getting an error group function is not allowed here How can I solve this problem? Answer Your query makes no sense (to me, at least). What does that average salary represent? Whose average salary? Here’…
Delete rows from 2 tables using a single query
I have the following database-schema: I have the following example data: CREATE TABLE computermapping ( ComputerMappingID int NOT NULL, PrinterGUID char(36) NOT NULL, ComputerGUID char(36) NOT …
Sqlite Query to remove duplicates from one column. Removal depends on the second column
Please have a look at the following data example: In this table, I have multiple columns. There is no PRIMARY KEY, as per the image I attached, there are a few duplicates in STK_CODE. Depending on the (min) column, I want to remove duplicate rows. According to the image, one stk_code has three different rows.…
How to keep only one entry among several in PostgreSQL database
I have a database that monitors a network (snapshots table, that contains a snapshot_date column). This production database was flooded by a faulty crontab, resulting in many snapshots for the same device every day. I don’t won’t to remove everything, but i want to keep only one snapshot per snaps…
Delete all duplicates except first one mysql
I have a table with a column serial_number that is repeated a few times. How would I delete the entire row except the first duplicate? By the following, I can select all the duplicates. But can’t delete. SELECT serial_number, COUNT(*) FROM trademark_merge GROUP BY serial_number HAVING COUNT(*) > 1 An…
How to cascade on delete in a foreign key of a mysql table correctly?
I have three tables with foreign keys which should cascade on delete nevertheless when I run this only the mapping in Tagmap and nothing happens in Excerpt nor Tag. What am I doing wrong? Answer This is not how foreign keys work. You delete from the parent table (here, tag, or excerpt), and then children reco…
Delete a task stored in SQL database through html form using Python
This is a web app written in Python to add and delete tasks. This is the add_tasks function: @app.route(“/add”, methods=[“GET”, “POST”]) @login_required def add(): …
SQLite Delete row from Table A when columns are referenced as FOREIGN KEYS in other Tables B, C, etc
So I have several tables, but will show only 2 as an example: Table G gNo | gName | gAddress G1 | Jean | Bonalbo G2 | Oscar | Berlin G3 | Edd | Brisbane G4 | Bob | California Table B gNo | …
Delete with inner join and trigger throw error: Can’t update table ‘table_b’ in stored function/trigger
Why the following error (Can’t update table ‘table_b’ in stored function/trigger because it is already used by statement which invoked this stored function/trigger) appears after i try to delete with inner join? Can i solve it? Answer I don’t see the point for a trigger here. The funct…