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28 gru 2010 · To get all rows wtih an empty datetime column you could do this: SELECT * FROM yourtable WHERE yourdatecolumn IS NULL
6 cze 2024 · MS SQL provides a function ISNULL to check for null values: SELECT id, name FROM Department WHERE ISNULL (code, '') = '' OR TRIM (code) = ''; The ISNULL function in MS SQL takes two arguments: the first is a value or column name, and the second is the default value if the first argument is null.
The SQL Server ISNULL() function lets you return an alternative value when an expression is NULL: SELECT ProductName, UnitPrice * (UnitsInStock + ISNULL(UnitsOnOrder, 0)) FROM Products;
10 gru 2019 · Lets look at the difference between Null and Empty as given below: Null can be a unknown value or an absence of a value, where as an Empty or Blank string is a value, but is just empty. Null can be used for string, Integer, date, or any fields in a database where as Empty is used for string fields.
17 lis 2015 · You can't get an empty string because you're returning the DATE value type from ISNULL. Per the docs, ISNULL. Returns the same type as check_expression. If a literal NULL is provided as check_expression, returns the datatype of the replacement_value.
It is important to understand that a NULL column value is different than having a blank (empty string) or 0 value in a column. eg. ' ' or (empty string) <> NULL, 0 <> NULL. Let’s take a look at a few examples to illustrate these points.
Use the LEN function to check for null or empty values. You can just use LEN(@SomeVarcharParm) > 0. This will return false if the value is NULL, '', or ' '. This is because LEN(NULL) returns NULL and NULL > 0 returns false. Also, LEN(' ') returns 0. See for yourself run:
