How do you implement caching in Linq to SQL?
My LINQ query result cache is probably just what you’re looking for. var q = from c in context.Customers where c.City == “London” select new { c.Name, c.Phone }; var result = q.Take(10).FromCache(); Pete.
sql
iCalendar “Field” list (for database schema based on iCalendar standard)
I’ve done this (for VEvents only, not supporting TODO items or Journal entires or anything like that). My implementation looks like this (after removing columns that are not specific to the question): — One table for each event. An event may have multiple rRules. Create Table [vEvent] (vEventID Integer Identity(1, 1) Not Null Constraint [vEvent.pk] … Read more
Indexing Null Values in PostgreSQL
You could try a partial index: CREATE INDEX idx_partial ON othertable (m_id) WHERE (col1 is not null and col2 is not null and col3 is not null); From the docs: http://www.postgresql.org/docs/current/interactive/indexes-partial.html
Update Statement using Join and Group By
You can try putting the group by inside of a subquery, then join by the “JobOrderID”, like this: UPDATE J SET J.StatusID = A.statusId FROM MKT_JobOrder J INNER JOIN ( SELECT J.JobOrderID , CASE WHEN SUM(DUV.VendorDUQuantity) = SUM(RD.InvoiceQuantity) THEN 1 ELSE J.StatusID END AS statusId FROM PLN_DU_Vendor DUV INNER JOIN ENG_Release R ON R.ReleaseID = … Read more
SQL (ORACLE): ORDER BY and LIMIT [duplicate]
Prior to 12.1, Oracle does not support the LIMIT or OFFSET keywords. If you want to retrieve rows N through M of a result set, you’d need something like: SELECT a.* FROM (SELECT b.*, rownum b_rownum FROM (SELECT c.* FROM some_table c ORDER BY some_column) b WHERE rownum <= <<upper limit>>) a WHERE b_rownum >= … Read more
Convert Comma Separated column value to rows
try this SELECT A.[id], Split.a.value(‘.’, ‘VARCHAR(100)’) AS String FROM (SELECT [id], CAST (‘<M>’ + REPLACE([string], ‘,’, ‘</M><M>’) + ‘</M>’ AS XML) AS String FROM TableA) AS A CROSS APPLY String.nodes (‘/M’) AS Split(a); refer here Converting a single comma separated row into multiple rows
JPA COUNT with composite primary key query not working
Use count(d.ertek) or count(d.id) instead of count(d). This can be happen when you have composite primary key at your entity.
SQL Server Index – Any improvement for LIKE queries?
Only if you add full-text searching to those columns, and use the full-text query capabilities of SQL Server. Otherwise, no, an index will not help.
Return only one row from the right-most table for every row in the left-most table
Use: SELECT u.id, u.name, MIN(t.spent) AS spent FROM USERS u JOIN TRANSACTIONS t ON t.uid = u.id GROUP BY u.id, u.name Mind that this will only return users who have at least one TRANSACTIONS record. If you want to see users who don’t have supporting records as well as those who do – use: SELECT … Read more
Can a table field contain a hyphen?
Yes, you can use punctuation, white space, international characters, and SQL reserved words if you use delimited identifiers: SELECT * FROM `my-table`; In MySQL, use the back-ticks. In standard SQL, use double-quotes. Or if you use MySQL you can set the ANSI_QUOTES SQL mode: SET SQL_MODE = ANSI_QUOTES; SELECT * FROM “my-table”;