In Oracle, an empty string is the same as null. Among other things, this means that the query you provided will not work, as it will resolve as trim(my_column) = null, which is always false.

Possible Duplicate: Why does Oracle 9i treat an empty string as NULL? I have a table in Oracle 10g named TEMP_TABLE with only two columns - id and description just for the sake of …

Mar 3, 2020 · NOT NULL constraint specifies that a column cannot contain NULL values. To add a NOT NULL constraint to an existing table by using the ALTER TABLE statement. ALTER …

In a "simple" CASE expression you compare one expression to one or more values; that doesn't work with NULL, as we know from the first week of SQL classes. The "searched" CASE …

NULL xx -- count of records with null timestamps NOT NULL yy -- count of records with non-null timestamps Is that possible? Update: The table is quite large, so efficiency is important. I could …

Apr 14, 2011 · 437 <> is Standard SQL-92; != is its equivalent. Both evaluate for values, which NULL is not -- NULL is a placeholder to say there is the absence of a value. Which is why you …

Dec 7, 2011 · IS [NOT] NULL meddles with the indexes of SQL statements in Oracle, is there any way I can replace IS NULL in an SQL statement? According to Oracle 9i Performance Tuning …

Dec 22, 2011 · Oracle B-Tree indexes don't have nulls, while bitmap indexes do. Oracle, however, also has Full Index Scan and Fast Full Index Scan access paths that in some cases can …

SQL NOT IN constraint and NULL values From the text of the question it appears that the problem was occurring in a SQL DML SELECT query, rather than a SQL DDL CONSTRAINT.

Apr 12, 2020 · Oracle SQL - Not null code is not working Asked 5 years, 6 months ago Modified 5 years, 6 months ago Viewed 11k times