大约有 44,000 项符合查询结果（耗时：0.0295秒） [XML]
How to change the foreign key referential action? (behavior)
...wrote something to make the statements for me. Figured I'd share:
SELECT
CONCAT('ALTER TABLE `' ,rc.TABLE_NAME,
'` DROP FOREIGN KEY `' ,rc.CONSTRAINT_NAME,'`;')
, CONCAT('ALTER TABLE `' ,rc.TABLE_NAME,
'` ADD CONSTRAINT `' ,rc.CONSTRAINT_NAME ,'` FOREIGN KEY (`',kcu.COLUMN_NAME,
'`) RE...
Why is extending native objects a bad practice?
... at all:
// new types
const AddMonoid = {
empty: () => 0,
concat: (x, y) => x + y,
};
const ArrayMonoid = {
empty: () => [],
concat: (acc, x) => acc.concat(x),
};
const ArrayFold = {
reduce: xs => xs.reduce(
type(xs[0]).monoid.concat,
type(xs[0])...
How to store arrays in MySQL?
... AS pfs_person_name,
cast(concat('[', group_concat(json_quote(fruit_name) ORDER BY fruit_name SEPARATOR ','), ']') as json) AS pfs_fruit_name_array
FROM
person
INNER JOIN person_fruit
ON person.person_id = person_fruit.pf_person
IN...
How can you determine how much disk space a particular MySQL table is taking up?
...eneric query where the maximum unit display is TB (TeraBytes)
SELECT
CONCAT(FORMAT(DAT/POWER(1024,pw1),2),' ',SUBSTR(units,pw1*2+1,2)) DATSIZE,
CONCAT(FORMAT(NDX/POWER(1024,pw2),2),' ',SUBSTR(units,pw2*2+1,2)) NDXSIZE,
CONCAT(FORMAT(TBL/POWER(1024,pw3),2),' ',SUBSTR(units,pw3*2+1,2)) T...
Troubleshooting “Illegal mix of collations” error in mysql
...de. For example, the following statement does not return an error:
SELECT CONCAT(utf8_column, latin1_column) FROM t1;
It returns a result that has a character set of utf8 and the same collation as utf8_column. Values of latin1_column are automatically converted to utf8 before concatenating.
...
Show constraints on tables command
...e_name = 'my_table'
Or for better formatted output use this:
select
concat(table_name, '.', column_name) as 'foreign key',
concat(referenced_table_name, '.', referenced_column_name) as 'references'
from
information_schema.key_column_usage
where
referenced_table_name is not null
...
How can I convert the “arguments” object to an array in JavaScript?
...s.length; ++i)
args[i] = arguments[i];
return args.sort();
}
Array.concat version (slowest):
function sortArguments() {
return Array.prototype.concat.apply([], arguments).sort();
}
share
|
...
SQL Query to concatenate column values from multiple rows in Oracle
Would it be possible to construct SQL to concatenate column values from
multiple rows?
10 Answers
...
Is it possible to get the non-enumerable inherited property names of an object?
...", "length", "constructor", "push", "slice", "indexOf", "sort", "splice", "concat", "pop", "unshift", "shift", "join", "toString", "forEach", "reduceRight", "toLocaleString", "some", "map", "lastIndexOf", "reduce", "filter", "reverse", "every", "hasOwnProperty", "isPrototypeOf", "valueOf", "__define...
How do you create a random string that's suitable for a session ID in PostgreSQL?
...ng is always 32 characters. If you wanted a string of length 64, you could concatenate 2 MD5 strings: SELECT concat(md5(random()::text), md5(random()::text)); And if you wanted somewhere in the middle (50 chars for example), you could take a substring of that: SELECT substr(concat(md5(...