大约有 41,000 项符合查询结果（耗时：0.0303秒） [XML]
How do I get bit-by-bit data from an integer value in C?
...s:
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char** argv)
{
unsigned
input = 0b0111u,
n_bits = 4u,
*bits = (unsigned*)malloc(sizeof(unsigned) * n_bits),
bit = 0;
for(bit = 0; bit < n_bits; ++bit)
bits[bit] = (input >...
T-SQL: Selecting rows to delete via joins
...
DELETE FROM TableA a WHERE [filter condition on TableA]
AND (a.BId IN (SELECT a.BId FROM TableB b JOIN TableA a
ON a.BId = b.BId
WHERE [filter condition on TableB]))
(Note Interbase doesn't support the AS keyword for aliases)
...
LEFT JOIN only first row
...rtist_id) will be the earliest.
So try something like this (untested...)
SELECT *
FROM feeds f
LEFT JOIN artists a ON a.artist_id = (
SELECT
MIN(fa.artist_id) a_id
FROM feeds_artists fa
WHERE fa.feed_id = f.feed_id
) a
...
SQL variable to hold list of integers
...e @listOfIDs table (id int);
insert @listOfIDs(id) values(1),(2),(3);
select *
from TabA
where TabA.ID in (select id from @listOfIDs)
or
declare @listOfIDs varchar(1000);
SET @listOfIDs = ',1,2,3,'; --in this solution need put coma on begin and end
select *
from TabA
where charindex(',' + C...
Effect of NOLOCK hint in SELECT statements
...
1) Yes, a select with NOLOCK will complete faster than a normal select.
2) Yes, a select with NOLOCK will allow other queries against the effected table to complete faster than a normal select.
Why would this be?
NOLOCK typically (...
How do I spool to a CSV formatted file using SQLPLUS?
...you want for numbers (avoid scientific notation on IDs)
spool myfile.csv
select table_name, tablespace_name
from all_tables
where owner = 'SYS'
and tablespace_name is not null;
Output will be like:
TABLE_PRIVILEGE_MAP ,SYSTEM
SYSTEM_PRIVILEGE_MAP...
How can I search (case-insensitive) in a column using LIKE wildcard?
...
SELECT *
FROM trees
WHERE trees.`title` COLLATE UTF8_GENERAL_CI LIKE '%elm%'
Actually, if you add COLLATE UTF8_GENERAL_CI to your column's definition, you can just omit all these tricks: it will work automatically.
...
SQL Query to concatenate column values from multiple rows in Oracle
...on on string aggregation techniques. A very common one is to use LISTAGG:
SELECT pid, LISTAGG(Desc, ' ') WITHIN GROUP (ORDER BY seq) AS description
FROM B GROUP BY pid;
Then join to A to pick out the pids you want.
Note: Out of the box, LISTAGG only works correctly with VARCHAR2 columns.
...
What is your favorite C programming trick? [closed]
.... you could make a string "object" like this:
struct X {
int len;
char str[1];
};
int n = strlen("hello world");
struct X *string = malloc(sizeof(struct X) + n);
strcpy(string->str, "hello world");
string->len = n;
here, we've allocated a structure of type X on the heap that is the...
SQL selecting rows by most recent date
...eturns a result set with ChargeId, ChargeType, and MostRecentServiceMonth
SELECT
CHARGEID,
CHARGETYPE,
MAX(SERVICEMONTH) AS "MostRecentServiceMonth"
FROM INVOICE
GROUP BY CHARGEID, CHARGETYPE
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