模式匹配符 LIKE,模式匹配符[NOT] LIKE 常用於模糊查詢,它判斷列值是否與指定的字符串格式匹配:
ASCII pattern matching with char column
CREATE TABLE t (col1 char(30))
INSERT INTO t VALUES ('Robert King')
SELECT *?
FROM t?
WHERE col1 LIKE '% King' ? -- returns 1 row
-- Unicode pattern matching with nchar column
CREATE TABLE t (col1 nchar(30))
INSERT INTO t VALUES ('Robert King')
SELECT *?
FROM t?
WHERE col1 LIKE '% King' ? -- no rows returned
-- Unicode pattern matching with nchar column and RTRIM
CREATE TABLE t (col1 nchar (30))
INSERT INTO t VALUES ('Robert King')
SELECT *?
FROM t?
WHERE RTRIM(col1) LIKE '% King' ? -- returns 1 row