-- -- 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; -- -- 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'); INSERT INTO CHAR_TBL (f1) VALUES ('c '); SELECT * FROM CHAR_TBL; SELECT c.* FROM CHAR_TBL c WHERE c.f1 <> 'a'; SELECT c.* FROM CHAR_TBL c WHERE c.f1 = 'a'; SELECT c.* FROM CHAR_TBL c WHERE c.f1 < 'a'; SELECT c.* FROM CHAR_TBL c WHERE c.f1 <= 'a'; SELECT c.* FROM CHAR_TBL c WHERE c.f1 > 'a'; SELECT c.* FROM CHAR_TBL c WHERE c.f1 >= 'a'; 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'); SELECT * FROM CHAR_TBL; -- -- 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"; SELECT '\101'::"char"; SELECT '\377'::"char"; SELECT 'a'::"char"::text; SELECT '\377'::"char"::text; SELECT '\000'::"char"::text; SELECT 'a'::text::"char"; SELECT '\377'::text::"char"; SELECT ''::text::"char";