chore: import upstream snapshot with attribution

server/core_backend-server/migrations/postgres_functions.go

@@ -0,0 +1,103 @@
+package migrations
+
+import "github.com/pocketbase/dbx"
+
+func createSQLiteEquivalentFunctions(db dbx.Builder) error {
+	if getDriverName(db) != "postgres" {
+		return nil
+	}
+
+	//PostgreSQL:
+	// 1. Check existance
+	sql := `SELECT EXISTS (SELECT 1 FROM pg_proc WHERE proname = 'uuid_generate_v7');`
+	var exists bool
+	if err := db.NewQuery(sql).Row(&exists); err != nil {
+		return err
+	} else if exists {
+		// The function already exists, no need to create it again
+		return nil
+	}
+
+	// Postgres:
+	// 2. Create function
+	funcDef := `
+	-- Enable built-in pgcrypto extension to use gen_random_bytes function
+	CREATE EXTENSION IF NOT EXISTS "pgcrypto";
+
+	-- Adding "nocase" collation to be compatible with SQLite's built-in "nocase" collation
+	CREATE COLLATION IF NOT EXISTS "nocase" (
+		provider = icu,          -- Specify ICU as the provider
+		locale = 'und-u-ks-level2', -- Undetermined locale, Unicode extension (-u-), collation strength (ks) level 2 (level2)
+		deterministic = false    -- Case-insensitive collations are typically non-deterministic
+	);
+
+	-- Alias [hex] to encode(..., 'hex')
+	CREATE OR REPLACE FUNCTION hex(data bytea)
+	RETURNS text
+	LANGUAGE SQL
+	IMMUTABLE
+	AS $$
+	SELECT encode(data, 'hex')
+	$$;
+
+	-- Alias [randomblob] to gen_random_bytes(...)
+	CREATE OR REPLACE FUNCTION randomblob(length integer)
+	RETURNS bytea
+	LANGUAGE SQL
+	IMMUTABLE
+	AS $$
+	SELECT gen_random_bytes(length)
+	$$;
+
+	-- Create the uuid_generate_v7 function
+	create or replace function uuid_generate_v7()
+		returns uuid
+		as $$
+		begin
+		-- use random v4 uuid as starting point (which has the same variant we need)
+		-- then overlay timestamp
+		-- then set version 7 by flipping the 2 and 1 bit in the version 4 string
+		return encode(
+			set_bit(
+			set_bit(
+				overlay(uuid_send(gen_random_uuid())
+						placing substring(int8send(floor(extract(epoch from clock_timestamp()) * 1000)::bigint) from 3)
+						from 1 for 6
+				),
+				52, 1
+			),
+			53, 1
+			),
+			'hex')::uuid;
+		end
+		$$
+		language plpgsql
+		volatile;
+	
+	-- Create json_valid function
+	CREATE OR REPLACE FUNCTION json_valid(text) RETURNS boolean AS $$
+	BEGIN
+		PERFORM $1::jsonb;
+		RETURN TRUE;
+	EXCEPTION WHEN others THEN
+		RETURN FALSE;
+	END;
+	$$ LANGUAGE plpgsql IMMUTABLE;
+
+	-- Create a json_query_or_null function that handles any types.
+	CREATE OR REPLACE FUNCTION json_query_or_null(p_input jsonb, p_query text) RETURNS jsonb AS $$
+		SELECT JSON_QUERY(p_input, p_query)
+	$$ LANGUAGE sql IMMUTABLE;
+
+	-- Create a json_query_or_null function that handles any types.
+	CREATE OR REPLACE FUNCTION json_query_or_null(p_input anyelement, p_query text) RETURNS jsonb AS $$
+	BEGIN
+		RETURN JSON_QUERY(p_input::text::jsonb, p_query);
+	EXCEPTION WHEN others THEN
+		RETURN NULL;
+	END;
+	$$ LANGUAGE plpgsql STABLE;
+	`
+	_, err := db.NewQuery(funcDef).Execute()
+	return err
+}