Oracle substr 函數(shù)用于從一個(gè)字符串中提取子字符串。它有兩個(gè)或三個(gè)參數(shù):
substr 函數(shù)的語法如下:
SUBSTR(source_string, start_position, [length])
示例:
SELECT SUBSTR('Hello, World!', 1, 5) FROM DUAL; -- 結(jié)果為 'Hello'
SELECT SUBSTR('Hello, World!', 8) FROM DUAL; -- 結(jié)果為 'World!'