大约有 45,000 项符合查询结果（耗时：0.0465秒） [XML]
Concatenate multiple result rows of one column into one, group by another column [duplicate]
...Simpler with the aggregate function string_agg() (Postgres 9.0 or later):
SELECT movie, string_agg(actor, ', ') AS actor_list
FROM tbl
GROUP BY 1;
The 1 in GROUP BY 1 is a positional reference and a shortcut for GROUP BY movie in this case.
string_agg() expects data type text as input. Other ...
MySQL Conditional Insert
...
If your DBMS does not impose limitations on which table you select from when you execute an insert, try:
INSERT INTO x_table(instance, user, item)
SELECT 919191, 123, 456
FROM dual
WHERE NOT EXISTS (SELECT * FROM x_table
WHERE user = ...
Grant execute permission for a user on all stored procedures in database?
...out having to call grant execute on the new stored procedure:
IF EXISTS (SELECT * FROM sys.database_principals WHERE name = N'asp_net')
DROP USER asp_net
GO
IF EXISTS (SELECT * FROM sys.database_principals
WHERE name = N'db_execproc' AND type = 'R')
DROP ROLE [db_execproc]
GO
--Create a databa...
Delete element in a slice
...d a slice while it is in range, it will induce some problem.
Old Answer:
chars := []string{"a", "a", "b"}
for i, v := range chars {
fmt.Printf("%+v, %d, %s\n", chars, i, v)
if v == "a" {
chars = append(chars[:i], chars[i+1:]...)
}
}
fmt.Printf("%+v", chars)
Expected :
[a a ...
Using XPATH to search text containing
...with plain XML and XSL files in Microsoft's XML Notepad:
<xsl:value-of select="count(//td[text()='&nbsp;'])" />
The value returned is 1, which is the correct value in my test case.
However, I did have to declare nbsp as an entity within my XML and XSL using the following:
<!DOCTYP...
Difference between const & const volatile
...be the status register for a serial port. Various bits will indicate if a character is waiting to be read or if the transmit register is ready to accept a new character (ie., - it's empty). Each read of this status register could result in a different value depending on what else has occurred in t...
string.IsNullOrEmpty(string) vs. string.IsNullOrWhiteSpace(string)
...
The best practice is selecting the most appropriate one.
.Net Framework 4.0 Beta 2 has a new IsNullOrWhiteSpace() method for
strings which generalizes the IsNullOrEmpty() method to also include other white
space besides empty string.
...
SQL: capitalize first letter only [duplicate]
...t only for displaying and do not need the actual data in table to change:
SELECT UPPER(LEFT(word,1))+LOWER(SUBSTRING(word,2,LEN(word))) FROM [yourtable]
Hope this helps.
EDIT: I realised about the '-' so here is my attempt to solve this problem in a function.
CREATE FUNCTION [dbo].[CapitalizeFi...
How can I unit test Arduino code?
...tiplex four 7 segment displays, one port driving the segments and a second selecting the display. The display code interfaces with the displays via SetSegmentData(char) and SetDisplay(char). I can mock these in my C++ test rig and check that I get the data I expect. For the target I use #define so t...
stringstream, string, and char* conversion confusion
...am.str().c_str() live in memory, and why can't it be assigned to a const char* ?
5 Answers
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