大约有 13,000 项符合查询结果（耗时：0.0131秒） [XML]
mysql update column with value from another table
...
Second possibility is,
UPDATE TableB
SET TableB.value = (
SELECT TableA.value
FROM TableA
WHERE TableA.name = TableB.name
);
share
|
improve this answer
|
...
How do I check to see if a value is an integer in MySQL?
...e REGEXP operator, matching the string to a regular expression. Simply do
select field from table where field REGEXP '^-?[0-9]+$';
this is reasonably fast. If your field is numeric, just test for
ceil(field) = field
instead.
...
Left Join With Where Clause
...ring away rows where the left join doesn't succeed. Move it to the join:
SELECT `settings`.*, `character_settings`.`value`
FROM `settings`
LEFT JOIN
`character_settings`
ON `character_settings`.`setting_id` = `settings`.`id`
AND `character_settings`.`character_id` = '1'
...
Easy way to concatenate two byte arrays
What is the easy way to concatenate two byte arrays?
12 Answers
12
...
XDocument.ToString() drops XML Encoding Tag
...
use this:
output.Text = String.Concat(xml.Declaration.ToString() , xml.ToString())
share
|
improve this answer
|
follow
...
SQL SELECT speed int vs varchar
...k: A=261MB B=292MB C=322MB
Non-indexed by id: select count(*), select by id: 450ms same on all tables
Insert* one row per TX: B=9ms/record C=9ms/record
Bulk insert* in single TX: B=140usec/record C=180usec/record
Indexed by id, select by id: B=about 2...
Default value in Go's method
...s
// Both parameters are optional, use empty string for default value
func Concat1(a string, b int) string {
if a == "" {
a = "default-a"
}
if b == 0 {
b = 5
}
return fmt.Sprintf("%s%d", a, b)
}
**Option 2:** A single optional parameter at the end
// a is required, b is optional...
Oracle SELECT TOP 10 records
I have an big problem with an SQL Statement in Oracle. I want to select the TOP 10 Records ordered by STORAGE_DB which aren't in a list from an other select statement.
...
Search for one value in any column of any table inside a database
...OT NULL
BEGIN
SET @ColumnName = ''
SET @TableName =
(
SELECT MIN(QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME))
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE'
AND QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME) &...
How to split a string literal across multiple lines in C / Objective-C?
...de it.
#define QUOTE(...) #__VA_ARGS__
const char *sql_query = QUOTE(
SELECT word_id
FROM table1, table2
WHERE table2.word_id = table1.word_id
ORDER BY table1.word ASC
);
the preprocessor turns this into:
const char *sql_query = "SELECT word_id FROM table1, table2 WHERE table2.wo...