drop extension if exists pg_query_rewrite;
--
create extension pg_query_rewrite;
select pgqr_truncate();
 pgqr_truncate 
---------------
 t
(1 row)

--
drop table if exists t;
create table t(x int, y int);
--
insert into t values(1,2);
--
select pgqr_add_rule('select 10;','select 11;');
 pgqr_add_rule 
---------------
 t
(1 row)

select pgqr_add_rule('select 1+1;','select 1+2;');
 pgqr_add_rule 
---------------
 t
(1 row)

select pgqr_add_rule('select x from t;','select x,y from t;');
 pgqr_add_rule 
---------------
 t
(1 row)

--
select 10;
 ?column? 
----------
       11
(1 row)

select 1+1;
 ?column? 
----------
        3
(1 row)

select x from t;
 x | y 
---+---
 1 | 2
(1 row)

--
select pgqr_remove_rule('select 1+1;');
 pgqr_remove_rule 
------------------
 t
(1 row)

select pgqr_rules();
                                             pgqr_rules                                             
----------------------------------------------------------------------------------------------------
 (datname=contrib_regression,"source=select 10;","target=select 11;",rewrite_count=1)
 (datname=contrib_regression,"source=select x from t;","target=select x,y from t;",rewrite_count=1)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
(10 rows)

select 1+1;
 ?column? 
----------
        2
(1 row)

--
select pgqr_remove_rule('select 10;');
 pgqr_remove_rule 
------------------
 t
(1 row)

select pgqr_rules();
                                             pgqr_rules                                             
----------------------------------------------------------------------------------------------------
 (datname=contrib_regression,"source=select x from t;","target=select x,y from t;",rewrite_count=1)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
(10 rows)

select 10;
 ?column? 
----------
       10
(1 row)

--
select pgqr_remove_rule('select x from t;');
 pgqr_remove_rule 
------------------
 t
(1 row)

select pgqr_rules();
                       pgqr_rules                       
--------------------------------------------------------
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
 (datname=NULL,source=NULL,target=NULL,rewrite_count=0)
(10 rows)

select x from t;
 x 
---
 1
(1 row)

--
select x from t;
 x 
---
 1
(1 row)

select 1+1;
 ?column? 
----------
        2
(1 row)

select 10;
 ?column? 
----------
       10
(1 row)