plpgsql

问题 I want to write a function that returns a table with all the rows between firstDate and lastDate . The rows have datatype timestamp without time zone They also have to be of a specific node id. This is my function: CREATE OR REPLACE FUNCTION get_measurements_by_node_and_date(nodeID INTEGER, firstDate date, lastDate date) RETURNS TABLE (measurement_id INTEGER, node_id INTEGER, carbon_dioxide DOUBLE PRECISION, hydrocarbons DOUBLE PRECISION, temperature DOUBLE PRECISION, humidity DOUBLE

问题 I want to write a function that returns a table with all the rows between firstDate and lastDate . The rows have datatype timestamp without time zone They also have to be of a specific node id. This is my function: CREATE OR REPLACE FUNCTION get_measurements_by_node_and_date(nodeID INTEGER, firstDate date, lastDate date) RETURNS TABLE (measurement_id INTEGER, node_id INTEGER, carbon_dioxide DOUBLE PRECISION, hydrocarbons DOUBLE PRECISION, temperature DOUBLE PRECISION, humidity DOUBLE

问题 Using Postgres 11.5, I've been looking at CREATE DOMAIN since yesterday, and would like to clarify how they can/can't help with function parameters. Ideally, I'd like to use a domain to screen parameter inputs easily, but with a helpful error response. As an example, I'm using a simple first-case, a domain that blocks null and empty strings: CREATE DOMAIN text_not_empty AS text NOT NULL CHECK (value <> ''); I tried this out as a field type for a table, and it's great. When we don't allow

问题 Using Postgres 11.5, I've been looking at CREATE DOMAIN since yesterday, and would like to clarify how they can/can't help with function parameters. Ideally, I'd like to use a domain to screen parameter inputs easily, but with a helpful error response. As an example, I'm using a simple first-case, a domain that blocks null and empty strings: CREATE DOMAIN text_not_empty AS text NOT NULL CHECK (value <> ''); I tried this out as a field type for a table, and it's great. When we don't allow

问题 First off, the iceberg-cube query is defined as in Let's say I have a relation item,location,year,supplier,unit_sales , and I would like to write a plpgsql functions as a wrapper around the query in the image, to specify the parameter N , like so: create or replace function iceberg_query( percentage integer ) returns cube /* Code here */ as $$ declare numrows int; begin select count(*) into numrows from sales; select item, location, year, count(*) from sales group by cube(item,location,year)

问题 First off, the iceberg-cube query is defined as in Let's say I have a relation item,location,year,supplier,unit_sales , and I would like to write a plpgsql functions as a wrapper around the query in the image, to specify the parameter N , like so: create or replace function iceberg_query( percentage integer ) returns cube /* Code here */ as $$ declare numrows int; begin select count(*) into numrows from sales; select item, location, year, count(*) from sales group by cube(item,location,year)

问题 So I wrote a Fibonacci sequence function like this: CREATE OR REPLACE FUNCTION fibonacci (lastN INTEGER) RETURNS int AS $$ BEGIN WITH RECURSIVE t(a, b) AS ( VALUES(0,1) UNION ALL SELECT GREATEST(a, b), a + b AS a from t WHERE b < $1 ) SELECT a FROM t; END; $$ LANGUAGE plpgsql; But when I called: SELECT * FROM fibonacci(20); the console shows: ERROR: query has no destination for result data HINT: If you want to discard the results of a SELECT, use PERFORM instead. CONTEXT: PL/pgSQL function

问题 So I wrote a Fibonacci sequence function like this: CREATE OR REPLACE FUNCTION fibonacci (lastN INTEGER) RETURNS int AS $$ BEGIN WITH RECURSIVE t(a, b) AS ( VALUES(0,1) UNION ALL SELECT GREATEST(a, b), a + b AS a from t WHERE b < $1 ) SELECT a FROM t; END; $$ LANGUAGE plpgsql; But when I called: SELECT * FROM fibonacci(20); the console shows: ERROR: query has no destination for result data HINT: If you want to discard the results of a SELECT, use PERFORM instead. CONTEXT: PL/pgSQL function

问题 I want to create a trigger which counts rows and updates a field in an other table. My current solution works for INSERT statements but failes when I DELETE a row. My current function: CREATE OR REPLACE FUNCTION update_table_count() RETURNS trigger AS $$ DECLARE updatecount INT; BEGIN Select count(*) into updatecount From source_table Where id = new.id; Update dest_table set count=updatecount Where id = new.id; RETURN NEW; END; $$ LANGUAGE 'plpgsql'; The trigger is a pretty basic one, looking

问题 I want to create a trigger which counts rows and updates a field in an other table. My current solution works for INSERT statements but failes when I DELETE a row. My current function: CREATE OR REPLACE FUNCTION update_table_count() RETURNS trigger AS $$ DECLARE updatecount INT; BEGIN Select count(*) into updatecount From source_table Where id = new.id; Update dest_table set count=updatecount Where id = new.id; RETURN NEW; END; $$ LANGUAGE 'plpgsql'; The trigger is a pretty basic one, looking