I want to create a function in pgsql that will take three parameters and return a single value (1 row, 1 col).
I have the query working but can not seem to find a proper example of creating a function to do this.
Take a look at the example on this page, or this one.
If you actually go through the documentation there are multiple example of various functions and return types.
Related
Is there a way in the V2 Copy Activity to operate upon one of the input columns (of type string) with an expression? Before I load rows to the destination, I need to limit the number of characters in the column.
My hope was to simply switch from something like this:
"ColumnMappings": "inColumn: outColumn"
to something like this:
"ColumnMappings": "#substring(inColumn, 1, 300): outColumn"
If anyone can point me to where I can read-up on where & when string expressions can be used, I could use the guidance.
This is the official documentation on expressions and functions: https://learn.microsoft.com/en-us/azure/data-factory/control-flow-expression-language-functions
And this is the documentation on mappings: https://learn.microsoft.com/en-us/azure/data-factory/copy-activity-schema-and-type-mapping
Also remember that if you are using a defined query in the copy activity, you can use sql functions like CAST([fieldName] as varchar(300)) to limit the amount of characters on a particular field.
Hope this helped!
When you don't have a SQL Source, but your destination is a SQL sink, you can use a Stored Procedure to insert your data into the final table. That way, you can define these kinds of transformations in the stored procedure. I don't think the Data Factory can handle these kinds of activities, it is more intended as an orchestrator.
Have a look here:
https://learn.microsoft.com/en-us/azure/data-factory/connector-sql-server#invoke-stored-procedure-from-sql-sink
I have a field in table in next format 1_2..1_10|1_6|1_8| where 1_2..1_10 include 1_2, 1_3 and other.
How I can select data, where number = 1_3?
1st suggestion: Get rights to modify the db structure and figure out how to better store the Navision string.
2nd suggestion: CLR
I'll assume you are relatively comfortable with each of these concepts. If you aren't they are very well documented all over the web.
My approach would be to use a CLR function as there's going to be some high level things that are awkward in SQL that C# takes care of quite easily. The psuedo walk through would go something like this.
Implementation
Create a CLR funciton and implement it on the SQL server instance.
Using SQL resultset change the query to look for the returned value of the CLR function based on the navision filter value where "1_3".
CLR Function Logic
Create a c# function that takes in the value of the filter field and returns a string value.
The CLR function splits the filter field by the | char into a list.
Inside the CLR function create a second list. Iterate over the first list. When you find a ranged string split it on the ".." and manually add every available value between the range to the second list. When you find a value that isnt' ranged simply add it to the second list.
Join the contents of the second list together on the "|" charecter.
Return the joined value.
SQL Logic
SELECT Field1,Field2...CLRFunctionName(FilterValue) AS FixedFilterValue FROM Sometable WHERE FixedFilterValue LIKE '%1_3%';
I need to change the value of a property when I query the database using EF4. I have a company code that gets returned and I need to translate it to another company code, if needed. So, there is a stored procedure that is used to do this currently. Here's the old select statement.
SELECT companyName, TranslateCompanyCode(companyCode) as newCompanyCode FROM companyTable where companyCode = 'AA';
TranslateCompanyCode is the stored proc that does the translation. I'd like to do this in my new code when needed. I think I might need to use a Model-Defined Function. Anyone know how I can do this?
For your scenario, I would use a JOIN. Model-defined functions are cool when you need to perform a quick function on a value (particularly without an additional query). From a performance standpoint, a JOIN will be faster and more efficient than trying to put the sub-query in a model-defined function - particularly if you are selecting more than 1 row at a time.
However, if you do still want to use Model defined functions, then this example should point you in the right direction as to how to run a query within the function. This implementation will also be more complex than just using a join but is an alternative.
I have a bunch of dimension tables that have unique ID and Name fields. I need a T-SQL function that returns an ID when passed a table name and a value for the name field.
I'm guessing the function would build a little query then execute it? Performance isn't an issue since this is a one time ETL thing.
Sounds like you want a scalar user defined function
There's a lot of other ways to do it though, and udf's certainly can have some perfomance issues.
I have a temporary table (or, say, a function which returns a table of values).
I want to execute some statements for each record in the table.
Can this be done without using cursors?
I'm not opposed to cursors, but would like a more elegant syntax\way of doing it.
Something like this randomly made-up syntax:
for (select A,B from #temp) exec DoSomething A,B
I'm using Sql Server 2005.
I dont think what you want to to is that easy.
What i have found is that you can create a scalar function taking the arguments A and B and then from within the function execute an Extended Stored Procedure. This might achieve what you want to do, but it seems that this might make the code even more complex.
I think for readibility and maintainability, you should stick to the CURSOR implementation.
I would look into changing the stored proc so that it can work against a set of data rather than a single row input.
Would CROSS/OUTER APPLY do what you want if you need RBAR processing.
It's elegant, but depends on what processing you need to do