Shulou(Shulou.com)06/02 Report--

This article introduces the knowledge of "the method of randomly fetching data from oracle". In the operation of actual cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

No matter on the Internet or in reality, I have a taste of loneliness, which is a kind of ORACLE random query 1.select * from (select * from tablename order by dbms_random.value) where rownum < N; Note: dbms_random is a package that can generate random values or strings. Value () is the most commonly used, and there are generally two uses of value (). The first function value return number; has no parameters and returns a value with a precision of 38 bits, ranging from 0.0 to 1.0, but not including 1.0. The following example: dbms_output.put_line (round (dbms_random.value*100)); the second value takes two parameters, the first refers to the lower limit and the second refers to the upper limit, which will generate a number from the lower limit to the upper limit, but does not include the upper limit, as follows: dbms_output.put_line (trunc (dbms_random.value (1101)); 2.select * from tablename sample (3) where rownum < 4

Select empno,empname from (select empno,empname from emp order by dbms_random.value ()) where rownum

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