Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
141 views
in Technique[技术] by (71.8m points)

sql - Creating a "Numbers Table" in MySQL

I'm trying to generate a big table of consecutive numbers in MySQL.

I just want 2 columns; a primary key and a numbers column with a range of 0-X, where X is very large. Approx. 64,000 rows should do it. I've tried this code with no success:

CREATE TABLE numbers (
   number           INT         NOT NULL
   CONSTRAINT XPKnumbers
      PRIMARY KEY CLUSTERED (number)
    )

INSERT INTO numbers (number) VALUES (0)

DECLARE @i          INT
SET @i = 20

WHILE 0 < @i
   BEGIN
      INSERT INTO numbers (number)
         SELECT number + (SELECT 1 + Max(number) FROM numbers)
            FROM numbers

      SET @i = @i - 1
   END

SELECT * FROM numbers

and I get this error:

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'CONSTRAINT XPKnumbers PRIMARY KEY CLUSTERED (number) ) INSERT INTO n' at line 3

Anybody have any suggestions to make this work?

Question&Answers:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

You are missing semicolons, commas, and even after correcting syntax it is still not a good idea to select max from the table every time just to insert one more row in a loop.

Drop that and use generators from http://use-the-index-luke.com/blog/2011-07-30/mysql-row-generator :

CREATE OR REPLACE VIEW generator_16
AS SELECT 0 n UNION ALL SELECT 1  UNION ALL SELECT 2  UNION ALL 
   SELECT 3   UNION ALL SELECT 4  UNION ALL SELECT 5  UNION ALL
   SELECT 6   UNION ALL SELECT 7  UNION ALL SELECT 8  UNION ALL
   SELECT 9   UNION ALL SELECT 10 UNION ALL SELECT 11 UNION ALL
   SELECT 12  UNION ALL SELECT 13 UNION ALL SELECT 14 UNION ALL 
   SELECT 15;

CREATE OR REPLACE VIEW generator_256
AS SELECT ( ( hi.n << 4 ) | lo.n ) AS n
     FROM generator_16 lo, generator_16 hi;

CREATE OR REPLACE VIEW generator_4k
AS SELECT ( ( hi.n << 8 ) | lo.n ) AS n
     FROM generator_256 lo, generator_16 hi;

CREATE OR REPLACE VIEW generator_64k
AS SELECT ( ( hi.n << 8 ) | lo.n ) AS n
     FROM generator_256 lo, generator_256 hi;

CREATE OR REPLACE VIEW generator_1m
AS SELECT ( ( hi.n << 16 ) | lo.n ) AS n
     FROM generator_64k lo, generator_16 hi;

And if for whatever reason you really need a table of numbers just do:

INSERT INTO numbers(number)
SELECT n FROM generator_64k WHERE n < 64000

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...