The CASE statement is the closest to IF in SQL and is supported on all versions of SQL Server. SELECT CAST( CASE WHEN Obsolete=”N” or InStock = ‘Y’ THEN 1 ELSE 0 END AS bit) as Saleable, * FROM Product You only need to use the CAST operator if you want the result as a … Read more
You can use OPENROWSET for this. Have a look. I’ve also included the sp_configure code to enable Ad Hoc Distributed Queries, in case it isn’t already enabled. CREATE PROC getBusinessLineHistory AS BEGIN SELECT * FROM sys.databases END GO sp_configure ‘Show Advanced Options’, 1 GO RECONFIGURE GO sp_configure ‘Ad Hoc Distributed Queries’, 1 GO RECONFIGURE GO … Read more
That would have to be: db.users.find({“name”: /.*m.*/}) Or, similar: db.users.find({“name”: /m/}) You’re looking for something that contains “m” somewhere (SQL’s ‘%‘ operator is equivalent to regular expressions’ ‘.*‘), not something that has “m” anchored to the beginning of the string. Note: MongoDB uses regular expressions which are more powerful than “LIKE” in SQL. With regular … Read more
DISTINCT ON is typically simplest and fastest for this in PostgreSQL. (For performance optimization for certain workloads see below.) SELECT DISTINCT ON (customer) id, customer, total FROM purchases ORDER BY customer, total DESC, id; Or shorter (if not as clear) with ordinal numbers of output columns: SELECT DISTINCT ON (2) id, customer, total FROM purchases … Read more
In SQL Server 2008 you can insert multiple rows using a single SQL INSERT statement. INSERT INTO MyTable ( Column1, Column2 ) VALUES ( Value1, Value2 ), ( Value1, Value2 ) For reference to this have a look at MOC Course 2778A – Writing SQL Queries in SQL Server 2008. For example: INSERT INTO MyTable … Read more
SELECT DATEADD(dd, 0, DATEDIFF(dd, 0, @your_date)) for example SELECT DATEADD(dd, 0, DATEDIFF(dd, 0, GETDATE())) gives me 2008-09-22 00:00:00.000 Pros: No varchar<->datetime conversions required No need to think about locale
If you are on SQL Server 2017 or Azure, see Mathieu Renda answer. I had a similar issue when I was trying to join two tables with one-to-many relationships. In SQL 2005 I found that XML PATH method can handle the concatenation of the rows very easily. If there is a table called STUDENTS SubjectID … Read more
SELECT name, email, COUNT(*) FROM users GROUP BY name, email HAVING COUNT(*) > 1 Simply group on both of the columns. Note: the older ANSI standard is to have all non-aggregated columns in the GROUP BY but this has changed with the idea of “functional dependency”: In relational database theory, a functional dependency is a … Read more
Why is it needed? When data is stored on disk-based storage devices, it is stored as blocks of data. These blocks are accessed in their entirety, making them the atomic disk access operation. Disk blocks are structured in much the same way as linked lists; both contain a section for data, a pointer to the … Read more
Syntax: ALTER TABLE {TABLENAME} ADD {COLUMNNAME} {TYPE} {NULL|NOT NULL} CONSTRAINT {CONSTRAINT_NAME} DEFAULT {DEFAULT_VALUE} WITH VALUES Example: ALTER TABLE SomeTable ADD SomeCol Bit NULL –Or NOT NULL. CONSTRAINT D_SomeTable_SomeCol –When Omitted a Default-Constraint Name is autogenerated. DEFAULT (0)–Optional Default-Constraint. WITH VALUES –Add if Column is Nullable and you want the Default Value for Existing Records. Notes: … Read more