在MySQL中创建“Numbers Table”
我正在尝试在MySQL中生成一个大的连续Numbers Table。
我只想要2列;一个主键和一个数字列,范围在0-X之间,其中X很大。大约 应该有64,000行。我尝试了以下代码,但没有成功:
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
我得到这个错误:
#1064-您的SQL语法有误;在第3行的“ CONSTRAINT XPKnumbers PRIMARY KEY
CLUSTERED(number))INSERT INTO n”附近检查与您的MySQL服务器版本相对应的手册以使用正确的语法。
有人对这项工作有任何建议吗?
回答:
您会丢失分号,逗号,即使在更正语法之后,每次仅在循环中再插入一行也不是一个好主意。
从http://use-the-index-luke.com/blog/2011-07-30/mysql-row-
generator删除并使用生成器:
CREATE OR REPLACE VIEW generator_16AS 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;
如果出于任何原因您确实需要数字表,请执行以下操作:
INSERT INTO numbers(number)SELECT n FROM generator_64k WHERE n < 64000
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