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How do I create a unique constraint that also allows nulls?
...et_AllowNull
UNIQUE (TicketID, TicketUnique);
If IssueID 1 has ticket 123, the UNIQUE constraint will be on values (123, NULL). If IssueID 2 has no ticket, it will be on (NULL, 2). Some thought will show that this constraint cannot be duplicated for any row in the table, and still allows multip...
Is JavaScript an untyped language?
...licit compiler interjection, the instruction will error during run-time.
"12345" * 1 === 12345 // string * number => number
Strongly typed means there is a compiler, and it wants you an explicit cast from string to integer.
(int) "12345" * 1 === 12345
In either case, some compiler's featur...
How Pony (ORM) does its tricks?
...
@randomsurfer_123 probably not, we just need some time to implement it (maybe a week), and there are other tasks that are more important to us.
– Alexander Kozlovsky
Mar 18 '16 at 10:43
...
How should I use try-with-resources with JDBC?
... = new PreparedStatementWrapper(con, query,
new Object[] { 123L, "TEST" }) {
@Override
protected void prepareStatement(Object... params) throws SQLException {
stat.setLong(1, Long.class.cast(params[0]));
stat.setString(2, String...
Regex that accepts only numbers (0-9) and NO characters [duplicate]
...
In Javascript this is allowing the value 123-456 (\d)*$
– theB3RV
Feb 20 '17 at 15:39
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What's the fastest way to merge/join data.frames in R?
...bases as well.
library(plyr)
library(data.table)
library(sqldf)
set.seed(123)
N <- 1e5
d1 <- data.frame(x=sample(N,N), y1=rnorm(N))
d2 <- data.frame(x=sample(N,N), y2=rnorm(N))
g1 <- sample(1:1000, N, replace = TRUE)
g2<- sample(1:1000, N, replace = TRUE)
d <- data.frame(d1, g1,...
Reference: Comparing PHP's print and echo
...
echo 125;
ECHO 125
multi-value echo compiles to multiple opcodes
echo 123, 456;
ECHO 123
ECHO 456
Note that multi-value echo doesn't concatenate its arguments, but outputs them one-by-one.
Reference: zend_do_print, zend_do_echo.
Runtime differences
ZEND_PRINT is implemented as follows (ps...
C# convert int to string with padding zeros?
...
Simply
int i=123;
string paddedI = i.ToString("D4");
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In Java, what is the best way to determine the size of an object?
...
123
You should use jol, a tool developed as part of the OpenJDK project.
JOL (Java Object Layo...
App Inventor 2 ECharts 拓展：基于 ECharts 强大的个性化数据图表展示 · ...
...页
资源下载
.aix 拓展下载：
cn.fun123.ECharts.aix
demo程序下载：
echats_demo.aia
注：2个拓展是共一个.aix拓展文件，里面分2个拓展组件，导入.aix效果如下：
ECharts.js 图表库非常的丰富，只有你想不到没有...