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在RDBMS下,下列SQL語法相當好用:
SELECT COUNT(DISTINCT colName) FROM tableName;
但是在Access卻不支援這樣的語法,如果遇到這樣的情形,可將語法改為:
select count(*) as [ipcount] from (select distinct ip from
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在RDBMS下,下列SQL語法相當好用:
SELECT COUNT(DISTINCT colName) FROM tableName;
但是在Access卻不支援這樣的語法,如果遇到這樣的情形,可將語法改為:
select count(*) as [ipcount] from (select distinct ip from
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