NVL(value, default) is the function you are looking for. select type, craft, sum(NVL(regular, 0) + NVL(overtime, 0) ) as total_hours from hours_t group by type, craft order by type, craft Oracle have 5 NULL-related functions: NVL NVL2 COALESCE NULLIF LNNVL NVL: NVL(expr1, expr2) NVL lets you replace null (returned as a blank) with a string … Read more
ALTER TABLE tbl REMOVE PARTITIONING; Source: ALTER TABLE Statement in MySQL Reference Manual
OK, from an application developer’s point of view, here’s what these settings do: QUOTED_IDENTIFIER This setting controls how quotation marks “..” are interpreted by the SQL compiler. When QUOTED_IDENTIFIER is ON then quotes are treated like brackets ([…]) and can be used to quote SQL object names like table names, column names, etc. When it … Read more
From your SQL query, I think you need to first group them all by what in PARTITION BY clause, order each group by Date. Then project each group to include each entry with its index. Then SelectMany to flatten all groups, then apply filter and finally project the result you want. You can see that … Read more
If the system is able to tell the end of the statement without the semicolon, omitting them does no harm. If the system gets confused, it matters. Since you’ve been able to leave them off, there isn’t apparently a problem. A lot depends on how you’re writing your SQL. If you’re writing single statements in, … Read more
Mediawiki changed from varchar to varbinary in early 2011: War on varchar. Changed all occurrences of varchar(N) and varchar(N) binary to varbinary(N). varchars cause problems (“Invalid mix of collations” errors) on MySQL databases with certain configs, most notably the default MySQL config.
Common measures of software complexity include Cyclomatic Complexity (a measure of how complicated the control flow is) and Halstead complexity (a measure of complex the arithmetic is). The “control flow” in a SQL query is best related to “and” and “or” operators in query. The “computational complexity” is best related to operators such as SUM … Read more
Apparently, I was too lazy to read to the end of the documentation… Further down, the documentation states: subquery A subquery is used only in conjunction with the XML keyword. When you specify a subquery, all values found by the subquery are used for pivoting. […] This will work PIVOT XML (AVG(salary) FOR (company) IN … Read more
The mystery is solved: the behavior I was observing is a known bug. I sent the same original post to a PostgreSQL-specific list and got this answer: This is a bug :-(. The parse analysis code seems to think that WITH can only be attached to the top level or a leaf-level SELECT within a … Read more
How much writing vs. reading of this table(s) do you expect? I’ve used a single audit table, with columns for Table, Column, OldValue, NewValue, User, and ChangeDateTime – generic enough to work with any other changes in the DB, and while a LOT of data got written to that table, reports on that data were … Read more