The manual states the values as: Low value: 4713 BC High value: 294276 AD with the caveat, as Chris noted, that -infinity is also supported. See the note later in the same page in the manual; the above is only true if you are using integer timestamps, which are the default in all vaguely recent … Read more
ApplicationId must be of type UniqueIdentifier. Your code works fine if you do: DECLARE @TTEST TABLE ( TEST UNIQUEIDENTIFIER ) DECLARE @UNIQUEX UNIQUEIDENTIFIER SET @UNIQUEX = NEWID(); INSERT INTO @TTEST (TEST) VALUES (@UNIQUEX); SELECT * FROM @TTEST Therefore I would say it is safe to assume that ApplicationId is not the correct data type.
Hashes are faster than B-Trees for cases where you have a known key value, especially a known unique value. Hashes should be used if the column in question is never intended to be scanned comparatively with < or > commands. Hashes are O(1) complexity, B-Trees are O(log n) complexity ( iirc ) , ergo, for … Read more
You can do select max(id)+1 when you do the insertion. For example: INSERT INTO Log (id, rev_no, description) VALUES ((SELECT MAX(id) + 1 FROM log), ‘rev_Id’, ‘some description’) Note that this will fail on an empty table since there won’t be a record with id is 0 but you can either add a first dummy … Read more
if you don’t use the WHERE clause all the records on the table will be affected
About null ‘anything’ NOT LIKE null yields null, not true. And only true qualifies for filter expressions in a WHERE clause. Most functions return null on null input (there are exceptions). That’s the nature of null in any proper RDBMS. If you desire a single expression, you could use: AND (column_default LIKE ‘nextval%’) IS NOT … Read more
MySQL docs on Flow Control Statements say: MySQL supports the IF, CASE, ITERATE, LEAVE LOOP, WHILE, and REPEAT constructs for flow control within stored programs. Docs on Stored Programs and Views say: Stored program definitions include a body that may use compound statements, loops, conditionals, and declared variables. Compound-Statement Syntax This section describes the syntax … Read more
Spark >= 2.4 You can skip zip udf and use arrays_zip function: df.withColumn(“vars”, explode(arrays_zip($”varA”, $”varB”))).select( $”userId”, $”someString”, $”vars.varA”, $”vars.varB”).show Spark < 2.4 What you want is not possible without a custom UDF. In Scala you could do something like this: val data = sc.parallelize(Seq( “””{“userId”: 1, “someString”: “example1”, “varA”: [0, 2, 5], “varB”: [1, 2, … Read more
The uniqueness can be enforced with a unique constraint. Whether or not the unique index is case-sensitive is defined by the server’s (or the table’s) collation. You can get the current collation of your database with this query: SELECT DATABASEPROPERTYEX(‘AdventureWorks’, ‘Collation’) SQLCollation; and you should get something like: SQLCollation ———————————— SQL_Latin1_General_CP1_CI_AS Here, the “CI_AS” at … Read more
Well, it won’t be a quick’n’easy way to do this, really…. My approach would be this: create a new table with identical structure – except for the ID column being BIGINT IDENTITY instead of INT IDENTITY —-[ put your server into exclusive single-user mode here; user cannot use your server from this point on ]—- … Read more