END;
$$ LANGUAGE PLPGSQL STRICT VOLATILE;
+
+-- convenience function for linking two tables, but copying column w into column x instead of "id"
+-- e.g. select migration_tools.handle_link2(:'migschema','asset_copy','barcode','test_foo','l_barcode','id','x_acp_id',false);
+CREATE OR REPLACE FUNCTION migration_tools.handle_link2 (TEXT,TEXT,TEXT,TEXT,TEXT,TEXT,TEXT,BOOLEAN) RETURNS VOID AS $$
+ DECLARE
+ table_schema ALIAS FOR $1;
+ table_a ALIAS FOR $2;
+ column_a ALIAS FOR $3;
+ table_b ALIAS FOR $4;
+ column_b ALIAS FOR $5;
+ column_w ALIAS FOR $6;
+ column_x ALIAS FOR $7;
+ btrim_desired ALIAS FOR $8;
+ proceed BOOLEAN;
+ BEGIN
+ EXECUTE 'SELECT EXISTS (
+ SELECT 1
+ FROM information_schema.columns
+ WHERE table_schema = $1
+ AND table_name = $2
+ and column_name = $3
+ )' INTO proceed USING table_schema, table_a, column_a;
+ IF NOT proceed THEN
+ RAISE EXCEPTION '%.% missing column %', table_schema, table_a, column_a;
+ END IF;
+
+ EXECUTE 'SELECT EXISTS (
+ SELECT 1
+ FROM information_schema.columns
+ WHERE table_schema = $1
+ AND table_name = $2
+ and column_name = $3
+ )' INTO proceed USING table_schema, table_b, column_b;
+ IF NOT proceed THEN
+ RAISE EXCEPTION '%.% missing column %', table_schema, table_b, column_b;
+ END IF;
+
+ EXECUTE 'ALTER TABLE '
+ || quote_ident(table_b)
+ || ' DROP COLUMN IF EXISTS ' || quote_ident(column_x);
+ EXECUTE 'ALTER TABLE '
+ || quote_ident(table_b)
+ || ' ADD COLUMN ' || quote_ident(column_x) || ' TEXT';
+
+ IF btrim_desired THEN
+ EXECUTE 'UPDATE ' || quote_ident(table_b) || ' b'
+ || ' SET ' || quote_ident(column_x) || ' = ' || quote_ident(column_w) || ' FROM ' || quote_ident(table_a) || ' a'
+ || ' WHERE BTRIM(a.' || quote_ident(column_a)
+ || ') = BTRIM(b.' || quote_ident(column_b) || ')';
+ ELSE
+ EXECUTE 'UPDATE ' || quote_ident(table_b) || ' b'
+ || ' SET ' || quote_ident(column_x) || ' = ' || quote_ident(column_w) || ' FROM ' || quote_ident(table_a) || ' a'
+ || ' WHERE a.' || quote_ident(column_a)
+ || ' = b.' || quote_ident(column_b);
+ END IF;
+
+ END;
+$$ LANGUAGE PLPGSQL STRICT VOLATILE;