Sample Data: Desire Data: how to write a sql to update the room seat number to serial num in MySQL 5.7? the room’s seat is from 2-20. Answer One option uses the update/join syntax. In MySQL 5.7, where window functions are not available, you can emulate row_number() with a correlated subquery (which is s…
Tag: sql-update
How to run a unique function to calculate and replace a null value in a database?
In the above database, I want to calculate the value for “A2” using the other 3 variables. The premise is that each column has a specific score with respect to each variable and the javascript would sum the answers in a row with a null blank in the A2 slot in this case. Answer You can implement th…
MYSQL no duplicate of 2 values
I couldn’t find an answer for this exact question although I am sure the information is on here somewhere. I have a python script that is adding stock data into a database. For each stock database has ~1000 lines where ‘ticker’ is the stock name and ‘time’ is the date(1 for each …
Logic for backward updation based on parent value
I have below tables with data as below Table_Cell Table_column Table_row I need to update SwitchCol in Table_column and Switchrow in Table_row Logic is If for an column_id in Table_column, all the combination with row_id in Table_row,present in table Table_Cell is 1, then make the SwitchCol =1 for that column…
Oracle – update data in first table with rows from second table
How to update ‘date_from’ (t1) using ‘modfied’ (t2) when it is like 20/07/20. So in this case in t1 id’s 1 and 2 are to be updated and id 3 stays. Table 1: id date_from ———————– 1 …
Using WITH and subset in CASE construction
Greetings to senior colleagues. I got caught up in this thing. It is necessary to substitute the corresponding values in the CASE when the construction depending on the state of the load_date field. The problem is that the second was assigned a value to the mean_v field based on the calculation of the average…
How update row with inner joins
I have this select statement where I found two rows, and I want to update a specific column: I have tried: How do I correctly construct the update query? SOLUTION: Answer Just put your query as a table: Here is a demo: DEMO
SQL – Update table column values using expression based on two tables
Using a Sqlite database, I have a users table and a ranks table with the following columns: users table: id | rankid | xp ranks table id | name | xpLowerLevel My goal is update the rankId field for all user rows based on the xpLowerLevel field from the ranks table. My Sql expression as follows: Which gives me…
Update SQL table using C#
I’m trying to update EpisodeId no:117 in the Episode table and it executes successfully but when I check the table it is not updated. int episode Id = 117; Answer There are some issues with your SQL update statement.Look at following for reference to Update Statement in SQL LINK There is also an easier …
is a LOCK TABLE needed for `UPDATE tbl SET col = col + 1`?
lets say that col is 0, and 100 clients is trying to increase it by 1 at the exact same time, is the LOCK TABLE needed here? or can i just do and be sure that col becomes 100? (eg that mariadb makes sure none of them reads the same value twice~) i’m basically trying to do the equivalent of