1DROP TABLE IF EXISTS t1; 2CREATE TABLE t1 ( 3c CHAR , 4c0 CHAR(0) , 5c1 CHAR(1) , 6c20 CHAR(20) , 7c255 CHAR(255) , 8PRIMARY KEY (c255) 9) ENGINE=rocksdb; 10SHOW COLUMNS IN t1; 11Field Type Null Key Default Extra 12c char(1) YES NULL 13c0 char(0) YES NULL 14c1 char(1) YES NULL 15c20 char(20) YES NULL 16c255 char(255) NO PRI 17INSERT INTO t1 (c,c0,c1,c20,c255) VALUES ('','','','',''); 18INSERT INTO t1 (c,c0,c1,c20,c255) VALUES ('a','','b','abcdefghi klmnopqrst', 'Creating an article for the Knowledgebase is similar to asking questions. First, navigate to the category where you feel the article should be. Once there, double check that an article doesn\'t already exist which would work.'); 19SELECT c,c0,c1,c20,c255 FROM t1; 20c c0 c1 c20 c255 21 22a b abcdefghi klmnopqrst Creating an article for the Knowledgebase is similar to asking questions. First, navigate to the category where you feel the article should be. Once there, double check that an article doesn't already exist which would work. 23INSERT INTO t1 (c,c0,c1,c20,c255) VALUES ('abc', 'a', 'abc', REPEAT('a',21), REPEAT('x',256)); 24Warnings: 25Warning 1265 Data truncated for column 'c' at row 1 26Warning 1265 Data truncated for column 'c0' at row 1 27Warning 1265 Data truncated for column 'c1' at row 1 28Warning 1265 Data truncated for column 'c20' at row 1 29Warning 1265 Data truncated for column 'c255' at row 1 30INSERT INTO t1 (c,c0,c1,c20,c255) SELECT c255, c255, c255, c255, CONCAT('a',c255,c1) FROM t1; 31Warnings: 32Warning 1265 Data truncated for column 'c' at row 5 33Warning 1265 Data truncated for column 'c0' at row 5 34Warning 1265 Data truncated for column 'c1' at row 5 35Warning 1265 Data truncated for column 'c20' at row 5 36Warning 1265 Data truncated for column 'c' at row 6 37Warning 1265 Data truncated for column 'c0' at row 6 38Warning 1265 Data truncated for column 'c1' at row 6 39Warning 1265 Data truncated for column 'c20' at row 6 40Warning 1265 Data truncated for column 'c255' at row 6 41SELECT c,c0,c1,c20,c255 FROM t1; 42c c0 c1 c20 c255 43 44 a 45C C Creating an article aCreating an article for the Knowledgebase is similar to asking questions. First, navigate to the category where you feel the article should be. Once there, double check that an article doesn't already exist which would work.b 46a a aaaaaaaaaaaaaaaaaaaa xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx 47a b abcdefghi klmnopqrst Creating an article for the Knowledgebase is similar to asking questions. First, navigate to the category where you feel the article should be. Once there, double check that an article doesn't already exist which would work. 48x x xxxxxxxxxxxxxxxxxxxx axxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx 49SELECT DISTINCT c20, REPEAT('a',LENGTH(c20)), COUNT(*) FROM t1 GROUP BY c1, c20; 50c20 REPEAT('a',LENGTH(c20)) COUNT(*) 51 2 52Creating an article aaaaaaaaaaaaaaaaaaa 1 53aaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaa 1 54abcdefghi klmnopqrst aaaaaaaaaaaaaaaaaaaa 1 55xxxxxxxxxxxxxxxxxxxx aaaaaaaaaaaaaaaaaaaa 1 56ALTER TABLE t1 ADD COLUMN c257 CHAR(257) ; 57ERROR 42000: Column length too big for column 'c257' (max = 255); use BLOB or TEXT instead 58DROP TABLE t1; 59CREATE TABLE t1(c1 CHAR(0) NOT NULL); 60INSERT INTO t1 VALUES('a'); 61Warnings: 62Warning 1265 Data truncated for column 'c1' at row 1 63SELECT * FROM t1; 64c1 65 66DROP TABLE t1; 67CREATE TABLE t1(a char(10) character set utf8 collate utf8_bin primary key); 68INSERT INTO t1 VALUES ('one'),('two'),('three'),('four'),('five'); 69SELECT * FROM t1 LIMIT 1 UNION SELECT * FROM t1; 70a 71five 72four 73one 74three 75two 76DROP TABLE t1; 77