大约有 49,000 项符合查询结果（耗时：0.0416秒） [XML]
MySQL Insert Where query
...INSERT INTO Users(weight, desiredWeight)
VALUES (160,145)
INSERT using a SELECT statement
INSERT INTO Users(weight, desiredWeight)
SELECT weight, desiredWeight
FROM AnotherTable
WHERE id = 1
share
|
...
List all sequences in a Postgres db 8.1 with SQL
...
The following query gives names of all sequences.
SELECT c.relname FROM pg_class c WHERE c.relkind = 'S';
Typically a sequence is named as ${table}_id_seq. Simple regex pattern matching will give you the table name.
To get last value of a sequence use the following query:...
MySQL LIKE IN()?
... might be more efficient, but you'd have to benchmark it to be sure, e.g.
SELECT * from fiberbox where field REGEXP '1740|1938|1940';
share
|
improve this answer
|
follow
...
How to retrieve the current value of an oracle sequence without increment it?
...
SELECT last_number
FROM all_sequences
WHERE sequence_owner = '<sequence owner>'
AND sequence_name = '<sequence_name>';
You can get a variety of sequence metadata from user_sequences, all_sequences and dba_...
how to exclude null values in array_agg like in string_agg using postgres?
...
SQL Fiddle
select
id,
(select array_agg(a) from unnest(canonical_users) a where a is not null) canonical_users,
(select array_agg(a) from unnest(non_canonical_users) a where a is not null) non_canonical_users
from (
SELE...
How do I perform an IF…THEN in an SQL SELECT?
How do I perform an IF...THEN in an SQL SELECT statement?
30 Answers
30
...
MySQL - Rows to Columns
...ms that I'll use for the rest of this post. This will be the base table:
select * from history;
+--------+----------+-----------+
| hostid | itemname | itemvalue |
+--------+----------+-----------+
| 1 | A | 10 |
| 1 | B | 3 |
| 2 | A | 9...
How to delete duplicates on a MySQL table?
...n an index is going to be slow for large tables. Wouldn't it be better to SELECT MAX(ID) FROM t GROUP BY unique and then JOIN to an exact match of ID to MAX(ID)?
– ebyrob
Nov 10 '16 at 16:31
...
How to use GROUP BY to concatenate strings in SQL Server?
...S (1,'B',8)
INSERT INTO #YourTable ([ID],[Name],[Value]) VALUES (2,'C',9)
SELECT
[ID],
STUFF((
SELECT ', ' + [Name] + ':' + CAST([Value] AS VARCHAR(MAX))
FROM #YourTable
WHERE (ID = Results.ID)
FOR XML PATH(''),TYPE).value('(./text())[1]','VARCHAR(MAX)')
,1,2,'') AS NameVa...
How to concatenate text from multiple rows into a single text string in SQL server?
...y, John, Sam
2 Alaina, Edward
I used the following T-SQL:
SELECT Main.SubjectID,
LEFT(Main.Students,Len(Main.Students)-1) As "Students"
FROM
(
SELECT DISTINCT ST2.SubjectID,
(
SELECT ST1.StudentName + ',' AS [text()]
FR...