SET search_path TO "prepared statements";
-- test function evaluation with parameters in an expression
PREPARE prepared_function_evaluation_insert(int) AS
	INSERT INTO prepare_func_table (key, value1) VALUES ($1+1, 0*random());
-- execute 7 times to trigger prepared statement usage
EXECUTE prepared_function_evaluation_insert(1);
EXECUTE prepared_function_evaluation_insert(2);
EXECUTE prepared_function_evaluation_insert(3);
EXECUTE prepared_function_evaluation_insert(4);
EXECUTE prepared_function_evaluation_insert(5);
EXECUTE prepared_function_evaluation_insert(6);
EXECUTE prepared_function_evaluation_insert(7);
SELECT key, value1 FROM prepare_func_table ORDER BY key, value1;
 key | value1
---------------------------------------------------------------------
 2   |      0
 3   |      0
 4   |      0
 5   |      0
 6   |      0
 7   |      0
 8   |      0
(7 rows)

TRUNCATE prepare_func_table;
-- make it a bit harder: parameter wrapped in a function call
PREPARE wrapped_parameter_evaluation(text,text[]) AS
	INSERT INTO prepare_func_table (key,value2) VALUES ($1,array_to_string($2,''));
EXECUTE wrapped_parameter_evaluation('key', ARRAY['value']);
EXECUTE wrapped_parameter_evaluation('key', ARRAY['value']);
EXECUTE wrapped_parameter_evaluation('key', ARRAY['value']);
EXECUTE wrapped_parameter_evaluation('key', ARRAY['value']);
EXECUTE wrapped_parameter_evaluation('key', ARRAY['value']);
EXECUTE wrapped_parameter_evaluation('key', ARRAY['value']);
EXECUTE wrapped_parameter_evaluation('key', ARRAY['value']);
SELECT key, value2 FROM prepare_func_table ORDER BY key, value2;
 key | value2
---------------------------------------------------------------------
 key | value
 key | value
 key | value
 key | value
 key | value
 key | value
 key | value
(7 rows)