大约有 43,000 项符合查询结果（耗时：0.0480秒） [XML]
Convert from enum ordinal to enum type
...diamonds and clubs! A C programmer would allocate 1 byte for each: 'const char CLUBS=0;' etc... Yes,a HashMap lookup is O(1), but the memory and CPU overhead of a HashMap, in this case make it many orders of magnitude slower and resource hungry than calling .values() directly! No wonder Java is suc...
How to do this in Laravel, subquery where in
...sider this code:
Products::whereIn('id', function($query){
$query->select('paper_type_id')
->from(with(new ProductCategory)->getTable())
->whereIn('category_id', ['223', '15'])
->where('active', 1);
})->get();
...
How do I safely pass objects, especially STL objects, to and from a DLL?
...ply specific packing. The compiler will still apply default packing if you select a pack value bigger than the one the compiler would have chosen, so if you pick a large packing value, a class can still have different packing between compilers. The solution for this is to use #pragma pack(1), which ...
Why does UITableViewCell remain highlighted?
...
In your didSelectRowAtIndexPath you need to call deselectRowAtIndexPath to deselect the cell.
So whatever else you are doing in didSelectRowAtIndexPath you just have it call deselectRowAtIndexPath as well.
- (void)tableView:(UITableVi...
Html List tag not working in android textview. what can i do?
...
Instead of using the pasted bullet character, it may be better to use the unicode character: output.append("\n\t\u2022");
– Matt McMinn
Mar 10 '13 at 17:14
...
The SQL OVER() clause - when and why is it useful?
...ated values and then join it back to the original rowset, i.e. like this:
SELECT
orig.[Partition],
orig.Value,
orig.Value * 100.0 / agg.TotalValue AS ValuePercent
FROM OriginalRowset orig
INNER JOIN (
SELECT
[Partition],
SUM(Value) AS TotalValue
FROM OriginalRowset
G...
How to check if a table exists in a given schema
... whether a table (or view) exists, and the current user has access to it?
SELECT EXISTS (
SELECT FROM information_schema.tables
WHERE table_schema = 'schema_name'
AND table_name = 'table_name'
);
The information schema is mainly useful to stay portable across major versions and...
Change limit for “Mysql Row size too large”
...rows of your
tables plus the length of other variable length fields (VARCHAR, VARBINARY, and TEXT type fields).
In my situation the offending blob table was around 16MB. Thus, the way I solved it was by adding a line to my.cnf that ensured I had at least 10x that amount and then some:
innodb_l...
MySQL Error 1215: Cannot add foreign key constraint
...
It could also be that the character set is different. I hade this problem where one column had the utf8 character set while the other had latin1. Easily fixed with ALTER TABLE Table CHARACTER SET = utf8 ; and ALTER TABLE Device CHANGE COLUMN ID ID CHA...
Get all table names of a particular database by SQL query?
...different sql dbms deal with schemas.
Try the following
For SQL Server:
SELECT TABLE_NAME
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE' AND TABLE_CATALOG='dbName'
For MySQL:
SELECT TABLE_NAME
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE' AND TABLE_SCHEMA='dbN...