📄 char.out
字号:
---- CHAR---- fixed-length by value-- internally passed by value if <= 4 bytes in storageSELECT 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, 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 ------+---- | A | 1 | 2 | 3 | (5 rows)SELECT '' AS six, c.* FROM CHAR_TBL c WHERE c.f1 <= 'a'; six | f1 -----+---- | a | A | 1 | 2 | 3 | (6 rows)SELECT '' AS one, c.* FROM CHAR_TBL c WHERE c.f1 > 'a'; one | f1 -----+---- | c(1 row)SELECT '' AS two, c.* FROM CHAR_TBL c WHERE c.f1 >= 'a'; two | f1 -----+---- | a | c(2 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, CHAR_TBL.*; four | f1 ------+------ | a | ab | abcd | abcd(4 rows)
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -