大约有 37,000 项符合查询结果（耗时：0.0400秒） [XML]
Versioning SQL Server database
...N to N+1. (These go in your version control system.) A _version_history_ table, something like
create table VersionHistory (
Version int primary key,
UpgradeStart datetime not null,
UpgradeEnd datetime
);
gets a new entry every time an upgrade script runs which corresponds to th...
Why was the switch statement designed to need a break?
...c is just a clean interface to standard assembly idioms. When writing jump table driven flow control, the programmer has the choice of falling through or jumping out of the "control structure", and a jump out requires an explicit instruction.
So, c does the same thing...
...
How to check if a variable is set in Bash?
... This answer is very confusing. Any practical examples on how to use this table?
– Ben Davis
Sep 27 '14 at 17:16
13
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Create new user in MySQL and give it full access to one database
... - This is the command used to create users and grant rights to databases, tables, etc.
ALL PRIVILEGES - This tells it the user will have all standard privileges. This does not include the privilege to use the GRANT command however.
dbtest.* - This instructions MySQL to apply these rights for use ...
Java: parse int value from a char
...ou take '2' - '0' you really just get 50 - 48 = 2. Have a look at an ASCII table in order to understand this principle better. Also, 'x' means get the ascii value of the character in Java.
– Kevin Van Ryckegem
May 13 '17 at 13:16
...
How can I read and parse CSV files in C++?
...::istream &in) {
std::vector<std::vector<std::string>> table;
std::string row;
while (!in.eof()) {
std::getline(in, row);
if (in.bad() || in.fail()) {
break;
}
auto fields = readCSVRow(row);
table.push_back(fields);
...
Count number of records returned by group by
... count(*) RecordsPerGroup,
COUNT(*) OVER () AS TotalRecords
from temptable
group by column_1, column_2, column_3, column_4
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What is the best way to solve an Objective-C namespace collision?
...not changing the address of the original symbol. Objective-C uses a lookup table to map class names to addresses, and it's a 1-1 mapping, so you can't have two classes with the same name. Thus, to load both classes, one of them must have their name changed. However, when other classes need to access...
Why should I capitalize my SQL keywords? [duplicate]
...nk the latter is more readable. You can easily separate the keywords from table and column names, etc.
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ActiveRecord: size vs count
...e way to go if you are using the data.
Example: Summary of a fully loaded table, titles of displayed data, etc.
size
It checks if the data was loaded (i.e. already in rails) if so, then just count it, otherwise it calls count. (plus the pitfalls, already mentioned in other entries).
def size
l...