大约有 19,000 项符合查询结果(耗时:0.0248秒) [XML]
SQL join: selecting the last records in a one-to-many relationship
					...mmend solving it:
SELECT c.*, p1.*
FROM customer c
JOIN purchase p1 ON (c.id = p1.customer_id)
LEFT OUTER JOIN purchase p2 ON (c.id = p2.customer_id AND 
    (p1.date < p2.date OR (p1.date = p2.date AND p1.id < p2.id)))
WHERE p2.id IS NULL;
Explanation: given a row p1, there should be no ro...				
				
				
							How to reset postgres' primary key sequence when it falls out of sync?
					...
-- Login to psql and run the following
-- What is the result?
SELECT MAX(id) FROM your_table;
-- Then run...
-- This should be higher than the last result.
SELECT nextval('your_table_id_seq');
-- If it's not higher... run this set the sequence last to your highest id. 
-- (wise to run a quick pg...				
				
				
							javascript find and remove object in array based on key value
					...been trying several approaches on how to find an object in an array, where ID = var, and if found, remove the object from the array and return the new array of objects.
                    
                    
                        
                            
                            ...				
				
				
							When and why I should use session_regenerate_id()?
					Why and when should I use the  session_regenerate_id()  function in php?
Should I always use it after I use the  session_start() ?
I've read that I have to use it to prevent session fixation, is this the only reason?
                    
                    
                        
          ...				
				
				
							How can I list all foreign keys referencing a given table in SQL Server?
					...s...
select 
    t.name as TableWithForeignKey, 
    fk.constraint_column_id as FK_PartNo, c.
    name as ForeignKeyColumn 
from 
    sys.foreign_key_columns as fk
inner join 
    sys.tables as t on fk.parent_object_id = t.object_id
inner join 
    sys.columns as c on fk.parent_object_id = c.object...				
				
				
							Retrieving the last record in each group - MySQL
					..._messages AS (
  SELECT m.*, ROW_NUMBER() OVER (PARTITION BY name ORDER BY id DESC) AS rn
  FROM messages AS m
)
SELECT * FROM ranked_messages WHERE rn = 1;
Below is the original answer I wrote for this question in 2009:
I write the solution this way:
SELECT m1.*
FROM messages m1 LEFT JOIN mes...				
				
				
							Get specific object by id from array of objects in AngularJS
					...s to get only one object from the array. So I d like for example Item with id 1.
                    
                    
                        
                            
                                
                                        17 Answers
                              ...				
				
				
							How can I get a channel ID from YouTube?
					...m my channel using the  YouTube Data API V3 .  
For that I need my channel ID.  
I've tried to find my channel ID from my YouTube account, and I failed in every single way.  
If anyone have a single tip for me, I would be incredible glad. 
                    
                    
             ...				
				
				
							Need to list all triggers in SQL Server database with table name and table's schema
					...
SELECT 
     sysobjects.name AS trigger_name 
    ,USER_NAME(sysobjects.uid) AS trigger_owner 
    ,s.name AS table_schema 
    ,OBJECT_NAME(parent_obj) AS table_name 
    ,OBJECTPROPERTY( id, 'ExecIsUpdateTrigger') AS isupdate 
    ,OBJECTPROPERTY( id, 'ExecIsDeleteTrigger') AS isdelete 
    ,OBJ...				
				
				
							mongodb group values by multiple fields
					...ems to $push to an array.
db.books.aggregate([
    { "$group": {
        "_id": {
            "addr": "$addr",
            "book": "$book"
        },
        "bookCount": { "$sum": 1 }
    }},
    { "$group": {
        "_id": "$_id.addr",
        "books": { 
            "$push": { 
                "...				
				
				
							