is it possible to pass table/list/json as argument to postgreSQL function from .net core API? The requirement is like for an invoice, there are multiple line items. so we want to save invoice first and then it's respective multiple line items. for line items, we have to either call postgreSQL function one by one and insert line item to DB. so just checking if SQL bulk inset like functionality is available in PostgreSQL.
CREATE FUNCTION test(table sometable)
RETURNS TABLE(id bigint, vendor_id bigint)
BEGIN
-- bulk or single insert multiple records from argument table into postgreSQL table
END;
Thanks,
So, I came to know that json can be passed to postgresql function and there are plenty of functionality is available to extract value from json in postgresql function makes life easy.
Related
I am trying to create a Postgres SQL-function which runs some routine for my database.
The SQL-function calls a plpgsql-function which creates several temporary tables, but doesn't return anything (RETURNS void).
One of the tables created by the plpgsql-function is supposed to be used in my sql-function.
CREATE OR REPLACE FUNCTION public.my_sql_function()
RETURNS text AS
$BODY$
select public.my_plpsql_function(); -- this returns void, but has created a temp table "tmp_tbl"
DROP TABLE IF EXISTS mytable CASCADE;
CREATE TABLE mytable (
skov_id int8 PRIMARY KEY,
skov_stor int4,
skov_areal_ha numeric,
virkningfra timestamp(0) without time zone,
plannoejagtighed float8,
vertikalnoejagtighed float8,
geom geometry(MultiPolygon,25832),
orig_geom geometry(Polygon, 25832)
);
INSERT INTO mytable
select * from tmp_tbl ....
$BODY$ LANGUAGE sql;
When I try to run the lines, I get the following error:
ERROR: relation "tmp_tbl" does not exist
pgAdmin underlines the line select * from tmp_tbl ... as the part with an error.
So the SQL-function doesn't notice that the plpsql-function has created a temporary table.
Is there a workaround?
Creating and accessing a table in the same SQL function is generally impossible. Makes no difference whether you create the table in the SQL function directly or in a nested function call. All objects must be visible to begin with.
There is a big, fat note at the top of the chapter Query Language (SQL) Functions in the manual pointing that out:
Note
The entire body of a SQL function is parsed before any of it is
executed. While a SQL function can contain commands that alter the
system catalogs (e.g., CREATE TABLE), the effects of such commands
will not be visible during parse analysis of later commands in the
function. Thus, for example, CREATE TABLE foo (...); INSERT INTO foo VALUES(...); will not work as desired if packaged up into a single
SQL function, since foo won't exist yet when the INSERT command is
parsed. It's recommended to use PL/pgSQL instead of a SQL function in
this type of situation.
Related:
Why can PL/pgSQL functions have side effect, while SQL functions can't?
Difference between language sql and language plpgsql in PostgreSQL functions
I think so it is not possible - and minimally it should not by possible in future versions. SQL functions are similar to views, and then references to database object should be valid in function's creating time.
There is not any workaround - if you need temp table, use PLpgSQL, or try to write your code without temp table (it can be much better).
I want to write a stored procedure in PostgreSQL that get input parameters and then select data based on conditions using that input parameter values. How I can achieve this easily?
I only have to use the PostgreSQL stored procedure and and not function for this
In PostgreSQL if we want to return result set in tabular format we have to use functions. they are best way designed to do this all functionality
I'm a real beginner when it comes to SQL and I'm currently trying to build a database using postgres. I have a lot of data I want to put into my database in JSON files, but I have trouble converting it into tables. The JSON is nested and contains many variables, but the behavior of jsonb_populate_record allows me to ignore the structure I don't want to deal with right now. So far I have:
CREATE TABLE raw (records JSONB);
COPY raw from 'home/myuser/mydocuments/mydata/data.txt'
create type jsonb_type as (time text, id numeric);
create table test as (
select jsonb_populate_record(null::jsonb_type, raw.records) from raw;
When running the select statement only (without the create table) the data looks great in the GUI I use (DBeaver). However it does not seem to be an actual table as I cannot run select statements like
select time from test;
or similar. The column in my table 'test' also is called 'jsonb_populate_record(jsonb_type)' in the GUI, so something seems to be going wrong there. I do not know how to fix it, I've read about people using lateral joins when using json_populate_record, but due to my limited SQL knowledge I can't understand or replicate what they are doing.
jsonb_populate_record() returns a single column (which is a record).
If you want to get multiple columns, you need to expand the record:
create table test
as
select (jsonb_populate_record(null::jsonb_type, raw.records)).*
from raw;
A "record" is a a data type (that's why you need create type to create one) but one that can contain multiple fields. So if you have a column in a table (or a result) that column in turn contains the fields of that record type. The * then expands the fields in that record.
I have been working on my code for our activity in our major comp sci subject. The task asks to update a certain field in the table in postgresql using stored procedure
I have already create a gettopemp() to retrieved the data in the table, and I want to retrieve the information of gettopemp() to my new stored procedure updatetopemp(). How to use stored procedure inside the stored procedure ???
If you want to pass a function name as a parameter and call that in your code, you'll have to use dynamic SQL.
I am writing trigger for record updation in Postgresql using plpgsql . In trigger, I am accessing one value column value like below
NEW.mobileno -- This is usual way.
Now my requirement is , I will be having 'mobileno' text in one variable called dyn_columnname
Using this NEW and dyn_columnname , I should be access like NEW.mobileno value.
How can I achieve this..?
You need to use dynamic sql:
execute _dyn_sql_string into _dyn_col_value using _dyn_col_name;
http://www.postgresql.org/docs/current/static/plpgsql-statements.html#PLPGSQL-STATEMENTS-EXECUTING-DYN
It's usually better to avoid ending up with this situation to begin with, that being said, because the resulting query plans cannot be cached as efficiently as the plans from non-dynamic triggers.
If you're simply iterating through columns, consider approaching this by using dynamic sql, not to write a dynamic trigger function, but to write a dynamic function that creates or replaces a non-dynamic trigger function instead.
If you're using this because of some kind of business logic, consider revisitng your schema to aboid the situation entirely.