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Set operations (union, intersection) on Swift array?
...ing> = Set(array2)
Swift 3.0+ can do operations on sets as:
firstSet.union(secondSet)// Union of two sets
firstSet.intersection(secondSet)// Intersection of two sets
firstSet.symmetricDifference(secondSet)// exclusiveOr
Swift 2.0 can calculate on array arguments:
set1.union(array2) //...
Joining two lists together
...eserves the order of the lists, but it doesn't remove any duplicates which Union would do.
This does change list a. If you wanted to preserve the original lists then you should use Concat (as pointed out in the other answers):
var newList = a.Concat(b);
This returns an IEnumerable as long as a i...
Union of dict objects in Python [duplicate]
How do you calculate the union of two dict objects in Python, where a (key, value) pair is present in the result iff key is in either dict (unless there are duplicates)?
...
MySQL table is marked as crashed and last (automatic?) repair failed
... This was a quick fix! Had a "bad" options table. Make sure that you select the correct database first !
– jyllstuart
Jan 10 '19 at 15:54
add a comment
...
App Inventor 2 中文网VIP专享内容 · App Inventor 2 中文网
... 实现上传文件到服务器全方案总结
【MySQL】App Inventor 2 如何连接MySQL数据库（阿里云数据库）
[【云图片】利用网络微数据库实现图片上传至云端及从云端下载]
[【AI云识图】利用云API进行AI识图]
【OCR识别】App Inventor 2 OCR ...
能否详细说明下数据库的应用？ - App Inventor 2 中文网 - 清泛IT社区，为创新赋能！
...说明太少，比如哪里有云数据库的提供商，或者云数据库如何私有部署，能否详细说说，我想很多人应该有网络数据库的需求的，比如1个多客户的登录。非常感谢！网络微数据库已经出过不少资料了，详见中文文档页面：https://...
How can you determine how much disk space a particular MySQL table is taking up?
...
For a table mydb.mytable run this for:
BYTES
SELECT (data_length+index_length) tablesize
FROM information_schema.tables
WHERE table_schema='mydb' and table_name='mytable';
KILOBYTES
SELECT (data_length+index_length)/power(1024,1) tablesize_kb
FROM information_schema....
How do I split a string so I can access item x?
...0,
PATINDEX('%|%', @products))
SELECT @individual
SET @products = SUBSTRING(@products,
LEN(@individual + '|') + 1,
LEN(@products))
END
ELSE
BEGIN
SET @individu...
ROW_NUMBER() in MySQL
...asy, but actually it kind of isn't).
I often plump for a null-self-join:
SELECT t0.col3
FROM table AS t0
LEFT JOIN table AS t1 ON t0.col1=t1.col1 AND t0.col2=t1.col2 AND t1.col3>t0.col3
WHERE t1.col1 IS NULL;
“Get the rows in the table for which no other row with matching col1,col2 has a hi...
Should I use the datetime or timestamp data type in MySQL?
...o with the native format. You can do calculations within MySQL that way
("SELECT DATE_ADD(my_datetime, INTERVAL 1 DAY)") and it is simple to change the format of the value to a UNIX timestamp ("SELECT UNIX_TIMESTAMP(my_datetime)") when you query the record if you want to operate on it with PHP.
...