大约有 46,000 项符合查询结果（耗时：0.0163秒） [XML]
MySQL Results as comma separated list
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You can use GROUP_CONCAT to perform that, e.g. something like
SELECT p.id, p.name, GROUP_CONCAT(s.name) AS site_list
FROM sites s
INNER JOIN publications p ON(s.id = p.site_id)
GROUP BY p.id, p.name;
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MySQL CONCAT returns NULL if any field contain NULL
...nvert the NULL values with empty string by wrapping it in COALESCE
SELECT CONCAT(COALESCE(`affiliate_name`,''),'-',COALESCE(`model`,''),'-',COALESCE(`ip`,''),'-',COALESCE(`os_type`,''),'-',COALESCE(`os_version`,'')) AS device_name
FROM devices
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Elegant way to combine multiple collections of elements?
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I think you might be looking for LINQ's .Concat()?
var combined = foo.Concat(bar).Concat(foobar).Concat(...);
Alternatively, .Union() will remove duplicate elements.
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MySQL and GROUP_CONCAT() maximum length
I'm using GROUP_CONCAT() in a MySQL query to convert multiple rows into a single string.
However, the maximum length of the result of this function is 1024 characters.
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How to concatenate and minify multiple CSS and JavaScript files with Grunt.js (0.3.x)
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concat.js is being included in the concat task's source files public/js/*.js. You could have a task that removes concat.js (if the file exists) before concatenating again, pass an array to explicitly define which files you wa...
Javascript Array Concat not working. Why?
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The concat method doesn't change the original array, you need to reassign it.
if ( ref instanceof Array )
this.refs = this.refs.concat( ref );
else
this.refs.push( ref );
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Can I concatenate multiple MySQL rows into one field?
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You can use GROUP_CONCAT:
SELECT person_id, GROUP_CONCAT(hobbies SEPARATOR ', ')
FROM peoples_hobbies
GROUP BY person_id;
As Ludwig stated in his comment, you can add the DISTINCT operator to avoid duplicates:
SELECT person_id, GROUP_CONCAT(D...
MySQL select with CONCAT condition
... query itself.
You can either repeat the expression:
SELECT neededfield, CONCAT(firstname, ' ', lastname) as firstlast
FROM users
WHERE CONCAT(firstname, ' ', lastname) = "Bob Michael Jones"
or wrap the query
SELECT * FROM (
SELECT neededfield, CONCAT(firstname, ' ', lastname) as firstlast
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Node.js vs .Net performance
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.NET List Concat vs AddRange
What is the difference between the AddRange and Concat functions on a generic List? Is one recommended over the other?
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