Does join work on NULL values?

Does join work on NULL values?

Does join work on NULL values?

As we have seen from the above examples joining NULL values does not work. Even though you have two NULL values SQL Server does not treat these as the same value. Internally a value of NULL is an unknown value and therefore SQL Server does not equate an unknown value being equal to another unknown value.

How do you handle NULL in join?

Method 1. Use of ISNULL function – Here we just capturing the NULL value using ISNULL() function @ run-time and replacing it by -1, -1 is just and example, You can use any value you want. The value you select should not be present in the table you are joining.

What happens when you join on NULL?

Null values in tables or views being joined never match each other. Since bit columns do not permit null values, a value of 0 appears in an outer join when there is no match for a bit column in the inner table. The result of a join of null with any other value is null.

Which join operation include NULL values?

In SQL Full Outer Join, all rows from both the tables are included. If there are any unmatched rows, it shows NULL values for them. We can understand efficiently using examples. Let’s create a sample table and insert data into it.


The IS NULL condition is used in SQL to test for a NULL value. It returns TRUE if a NULL value is found, otherwise it returns FALSE. It can be used in a SELECT, INSERT, UPDATE, or DELETE statement.

How do I check for null in SQL Server?

In order to check for NULL values, you must use IS NULL or IS NOT NULL clause. For example, to include the row with Id as NULL, you can modify your SQL query like. SELECT * FROM #temp WHERE id != 1 OR id IS NULL Output id 2 NULL. You can see that it returned both rows.

How do I insert a null value in SQL?

In sql code: INSERT INTO [tablename] ([Column1]) VALUES (NULL) GO. In Sql management studio: Edit the table data. Navigate to the cell using mouse / keyboard, press Ctrl and zero, and then move the cursor using keys up or down, and null will be saved (if the column allows nulls) otherwise it will raise an error.

Where is not null SQL?

SQL IS NULL Clause. NULL is a special value that signifies ‘no value’. Comparing a column to NULL using the = operator is undefined. Instead, use WHERE IS NULL or WHERE IS NOT NULL.

What are the null values in a SQL Server?

A null value in a relational database is used when the value in a column is unknown or missing. A null is neither an empty string (for character or datetime data types) nor a zero value (for numeric data types). The ANSI SQL-92 specification states that a null must be the same for all data types, so that all nulls are handled consistently.