--
-- CHAR
--
-- fixed-length by value
-- internally passed by value if <= 4 bytes in storage
SELECT char 'c' = char 'c' AS true;
 true 
------
 t
(1 row)

--
-- Build a table for testing
--
CREATE 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 '' AS seven, * FROM CHAR_TBL;
 seven | f1 
-------+----
       | a
       | A
       | 1
       | 2
       | 3
       |  
       | c
(7 rows)

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

SELECT '' AS one, c.*
   FROM CHAR_TBL c
   WHERE c.f1 = 'a';
 one | f1 
-----+----
     | a
(1 row)

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

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

SELECT '' AS one, c.*
   FROM CHAR_TBL c
   WHERE c.f1 > 'a';
 one | f1 
-----+----
     | A
     | c
(2 rows)

SELECT '' AS two, c.*
   FROM CHAR_TBL c
   WHERE c.f1 >= 'a';
 two | f1 
-----+----
     | a
     | A
     | c
(3 rows)

DROP TABLE CHAR_TBL;
--
-- Now test longer arrays of char
--
CREATE TABLE CHAR_TBL(f1 char(4));
INSERT INTO CHAR_TBL (f1) VALUES ('a');
INSERT INTO CHAR_TBL (f1) VALUES ('ab');
INSERT INTO CHAR_TBL (f1) VALUES ('abcd');
INSERT INTO CHAR_TBL (f1) VALUES ('abcde');
ERROR:  value too long for type character(4)
INSERT INTO CHAR_TBL (f1) VALUES ('abcd    ');
SELECT '' AS four, * FROM CHAR_TBL;
 four |  f1  
------+------
      | a   
      | ab  
      | abcd
      | abcd
(4 rows)