There is 4 cases: (For example I’m talking about ON DELETE) CASCADE: the referencing rows will be deleted automatically along with the referenced ones. SET NULL: the value of referencing record will be set to NULL automatically along with the referenced ones. NO ACTION: There will not be any change in t…
Tag: sql
Select only 5 random rows in the last 50 entries
I’m just starting with MySQL so I would like to know how can I select only 5 random rows in the last 50 entries of my database? I hope you understand my question. I’m using PDO and what I have now is …
how django ‘auto_now’ ignore the update of specified field
i have a model, like this: name = models.CharField(max_length=255) modify_time = models.DateTimeField(auto_now=True) chasha = models.CharField(max_length=255) stat = models.CharField(…
How to create heat map on a table in SSRS?
How can I create like this in SSRS? The color will change from red to green based on a value in a row (Underwriter). And all that in a group: Answer You can do this by right clicking on the individual cells and setting the fill colour based on an expression: In the Image below I’ve mistakingly put ̶…
Can’t delete a row using entity framework
The problem that I’m having is that I can’t delete a row when using entity. I’m able to find the row, but the error I get the next error: Additional information: Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted si…
What is the difference between cube, rollup and groupBy operators?
I can’t find any detailed documentation regarding the differences. I do notice a difference, because when interchanging cube and groupBy function calls, I get different results. I noticed that for the result using cube, I got a lot of null values on the expressions where I used to use groupBy. Answer Th…
Perform same SQL query on multiple databases
I’m trying to adapt an SQL query to check the value present in a certain field that is present in every database on my server. There are 100 individual databases, and I would like to check a specific record of each one. The answer is probably to use a command like the one below, but I’m having dif…
Removing last character in ACCESS if it is “.”
I am trying to write an update query that will remove the last character if it is a period (“.”). In EXCEL, I would use the following statement: How can I modify this for ACCESS? I found the following statement in a forum, but ACCESS seems to have a problem with “Substring” and wonR…
How to get the schema name when I have table name – Oracle
I have a table name but I am not sure in which schema that table exists. How to find the schema name?
?? Combine, join, insert in query Access 2007-2010?
I have two tables that I would like to make into one table. TABLE WASP_COLOR1 TABLE WASP_COLOR2 I’m a novice and I need clear direction on how to obtain these results. (I want the duplicates merged.) TABLE WASP_COLOR1 I tried the following: Received error I tried: Received 9 rows instead of 5 I tried: T…