Hi all,

 

I am working a lot with custom procedures/functions which are implemented in 
"language sql". At the moment function parameter refs cannot work with 
parameter names. I would like to try to implement this. The actual TODO item is:

 

Allow SQL-language functions to reference parameters by parameter name 

Currently SQL-language functions can only refer to dollar parameters, e.g. $1 

 

After a quick look at how ref parameters in plpgsql and sql function are 
handled, I would like to start a discussion about the following implementation 
plan.

 

Implementation of the name parameter parsing in scan.l/gram.y can be achieved 
by adopting the same mechanism as plpgsql does. If I am not mistaking plpgsql 
parser creates a stack to store parameter identifiers.

 

Correct me if this would be wrong or not possible, but I am thinking of mapping 
the name references to the parameter numbers (par2 => $2) this way I hope to 
keep the implementation small and perhaps extend "struct ParamRef" to hold a 
possible parameter name.

 

Then there is the issue of error reporting for ambiguous parameter names (non 
existing parameter names and names which conflict with actual column names). I 
guess this can be handeled in "fmgr_sql_validator"

 

Please let me know your opinion.



Regards,

Gevik.

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