Mysql – Getting all rows where a key occurs only once among all columns
column1 column2 A 1 A 2 A 3 B 1 C 1 C 2 D 1 I want a query that prints column1 column2 B 1 D 1 Since B and D occur just once in the table. I have…
Mysql – how to solve the below CTE syntax error for the mentioned query
I have a sample query. I have tried to rewrite it with CTE but some errors occurred. Please check and solve the below query. actual query; select dt.population, dt.name, c.name from ( select distinct countrycode, name from city ) as…
MySQL DB – how to group by firstName and surName columns in my select query?
Could you please help me with group by firstName and surName columns in my select query ? to view 4 rows instead of 8 rows without NULL values i joined these two tables in MySQL: CREATE TABLE IF NOT EXISTS…
Postgresql – Obtaining original ID after aggregate operation (SQL)
Say I have a query: SELECT column_1, column_2 max(column_3) as max_column_3 FROM table_1 GROUP BY column_1, column_2 and I'm interested in returning the id of each row, instead of just column_1, column_2 max(column_3). When I try: SELECT id, column_1, column_2…
Postgresql – How to get a recursive tree for a single table element
I have a table of this type | id | parent_id | | title | parent_id refers to the id of the same table I need to get a recursive tree for an element knowing only its parent. it will…
Mysql – How can I update a column based on a calculation of other columns in a table?
I would like to give each player a rank / position based on the values of other columns, 1 being the best position. Each prize or penalty is worth a different amount. Can this be done in SQL and how…
Mysql – Python/ Teradata SQL: Extract data from a table and then do some analysis and put them in a table and then put the related data in other table
I have a main table which contains all columns student id name subject marks class 123 John Maths 56 7 234 Meth Maths 78 8 456 Jes Science 67 7 678 Tom Science 89 8 879 Ria Maths 92 7…
PostgreSQL Return Id from t1 where none of the inner join rows from t2 match second condition
t1 (Properties) | Id | Name | | - | ------ | | 31 | Garage | | 32 | Depot | | 33 | Store | t2 (Addresses) | Id | Prop_Id | Primary | | - | -------…
Postgresql – Unexpected error when trying to parse string
I have this table in PostgreSQL: Table_T: id body 1 bla bla bla Call ID: xxx Interaction ID: vvv bla bla 2 bla bla bla Call ID: zzz Interaction ID: ooo bla bla This is the output I am expecting:…
Mysql – Nested MariaDB Query Slow
I am having performance issues with a query, I have 21 million records across the table, and 2 of the tables I'm looking in here have 8 million each; individually, they are very quick. But I've done a query that,…