I've made a query to count and rank every row for a table, but I can't join the query into one table. I've been trying to make a leaderboard and I've managed to make a query that ranks every row…
I'm working on a transport program that forces me to create a long query to search for possible routes. I need to optimize the query as much as possible. It calculates stopovers between bus stops. People get off at one…
Assume I have two tables: cameraNum roadNum isWorking 100 1 TRUE 101 1 FALSE 102 1 TRUE 103 3 FALSE 104 3 FALSE 105 7 TRUE 106 7 TRUE 107 7 TRUE 108 9 FALSE 109 9 FALSE 110 9…
I can't get the REPLACE function to work on my SQL command shown here. I want it to take my search term (55512) and search for this in the field using the modified field from the regexp to remove all…
In Postgresql, suppose I have a 2-col table containing 3 records, namely tA id | col_A | col_B | type 1 | 1 | 2 | A 2 | 3 | 4 | B 3 | 3 | 1 |…
My query goes over three entities, so I have two left joins. I want to restrict the result of the first join. For example we have customers and order evaluations. In the first join I want only the youngest order…
On running the following MySQL (5.7.12) UPDATE statement, I get the error "Error Code: 1054. Unknown column 't1.col2' in 'where clause'". How can I rephrase this query such that the columns of t1 are accessible in the subquery? UPDATE MyFirstTable…
I have a Users table (id, name, created_at) and a Transaction table(id, user_id, created_at, amount). For each month, I would like to know the number of users who did not have any transaction in the 3 months interval before that…
Why must I state the table I'm referring to TWICE when using a join on a query? select table1.name from table1 inner join table2 on etc ...
I have below tables DEMO fiddle In x_table, I have different records. I want to fetch all currencies from x_table where continent is Asia which is straight forward as below, SELECT currency from x_table where continent='Asia' and it should return…