--
-- CHAR
--
-- Per SQL standard, CHAR means character(1), that is a varlena type
-- with a constraint restricting it to one character (not byte)
SELECT char 'c' = char 'c' AS true;
 true 
------
 t
(1 row)

--
-- Build a table for testing
-- (This temporarily hides the table created in test_setup.sql)
--
CREATE TEMP TABLE CHAR_TBL(f1 char);
INSERT INTO CHAR_TBL (f1) VALUES ('a');
INSERT INTO CHAR_TBL (f1) VALUES ('A');
-- any of the following three input formats are acceptable
INSERT INTO CHAR_TBL (f1) VALUES ('1');
INSERT INTO CHAR_TBL (f1) VALUES (2);
INSERT INTO CHAR_TBL (f1) VALUES ('3');
-- zero-length char
INSERT INTO CHAR_TBL (f1) VALUES ('');
-- try char's of greater than 1 length
INSERT INTO CHAR_TBL (f1) VALUES ('cd');
ERROR:  value too long for type character(1)
INSERT INTO CHAR_TBL (f1) VALUES ('c     ');
SELECT * FROM CHAR_TBL;
 f1 
----
 a
 A
 1
 2
 3
  
 c
(7 rows)

SELECT c.*
   FROM CHAR_TBL c
   WHERE c.f1 <> 'a';
 f1 
----
 A
 1
 2
 3
  
 c
(6 rows)

SELECT c.*
   FROM CHAR_TBL c
   WHERE c.f1 = 'a';
 f1 
----
 a
(1 row)

SELECT c.*
   FROM CHAR_TBL c
   WHERE c.f1 < 'a';
 f1 
----
 1
 2
 3
  
(4 rows)

SELECT c.*
   FROM CHAR_TBL c
   WHERE c.f1 <= 'a';
 f1 
----
 a
 1
 2
 3
  
(5 rows)

SELECT c.*
   FROM CHAR_TBL c
   WHERE c.f1 > 'a';
 f1 
----
 A
 c
(2 rows)

SELECT c.*
   FROM CHAR_TBL c
   WHERE c.f1 >= 'a';
 f1 
----
 a
 A
 c
(3 rows)

DROP TABLE CHAR_TBL;
--
-- Now test longer arrays of char
--
-- This char_tbl was already created and filled in test_setup.sql.
-- Here we just try to insert bad values.
--
INSERT INTO CHAR_TBL (f1) VALUES ('abcde');
ERROR:  value too long for type character(4)
SELECT * FROM CHAR_TBL;
  f1  
------
 a   
 ab  
 abcd
 abcd
(4 rows)

-- Also try it with non-error-throwing API
SELECT pg_input_is_valid('abcd  ', 'char(4)');
 pg_input_is_valid 
-------------------
 t
(1 row)

SELECT pg_input_is_valid('abcde', 'char(4)');
 pg_input_is_valid 
-------------------
 f
(1 row)

SELECT * FROM pg_input_error_info('abcde', 'char(4)');
               message                | detail | hint | sql_error_code 
--------------------------------------+--------+------+----------------
 value too long for type character(4) |        |      | 22001
(1 row)

--
-- Also test "char", which is an ad-hoc one-byte type.  It can only
-- really store ASCII characters, but we allow high-bit-set characters
-- to be accessed via bytea-like escapes.
--
SELECT 'a'::"char";
 char 
------
 a
(1 row)

SELECT '\101'::"char";
 char 
------
 A
(1 row)

SELECT '\377'::"char";
 char 
------
 \377
(1 row)

SELECT 'a'::"char"::text;
 text 
------
 a
(1 row)

SELECT '\377'::"char"::text;
 text 
------
 \377
(1 row)

SELECT '\000'::"char"::text;
 text 
------
 
(1 row)

SELECT 'a'::text::"char";
 char 
------
 a
(1 row)

SELECT '\377'::text::"char";
 char 
------
 \377
(1 row)

SELECT ''::text::"char";
 char 
------
 
(1 row)