Column fields that are part of a join convert to null or 0 when exported

Why does the attribute table have null or empty values after a join?

After performing a join, the values in the fields from the joined table might appear empty or null. Null values can be the result of several factors: Values in the specified fields for the join do not match. Joins are case sensitive, so be aware of this when using string fields to create a join.

How does inner join work with null values?

Columns containing NULL do not match any values when you are creating an inner join and are therefore excluded from the result set. Null values do not match other null values.

How do I join tables in Arcgis pro?

Joining attributes in one table to another

1. In the table of contents, right-click the layer or table you want to join, point to Joins and Relates, then click Join.
2. Click the What do you want to join to this layer?
3. Click the field on which the join will be based.
4. Choose the table to join to the layer or table.

How do I change data type in Arcgis pro?

Use the workflow below to change the data type from Long Integer to Short Integer.

1. Open the Feature Class to Feature Class tool.
2. In the Parameters section, specify the desired feature class for Input Features.
3. Specify a desired geodatabase for the Output Location.
4. Specify a name for the Output Feature Class.

How do you handle NULL values in SQL joins?

The result of a join of null with any other value is null. Because null values represent unknown or inapplicable values, Transact-SQL has no basis to match one unknown value to another. You can detect the presence of null values in a column from one of the tables being joined only by using an outer join.

Which join allows NULLs?

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.
 

Does join return NULL?

The SQL LEFT JOIN returns all rows from the left table, even if there are no matches in the right table. This means that if the ON clause matches 0 (zero) records in the right table; the join will still return a row in the result, but with NULL in each column from the right table.

Does join return NULL values?

An inner join returns the rows which match on the values in each join column from table A and table B. NULL values don’t match other NULL values so they are excluded from the results.

Can we use Isnull in join condition?

Although the ISNULL function is handy, if you are doing large joins having this function in the join clause will slow down the query. A lot of this will also depend on the indexes you have setup and how the indexes are used for the join.
 

What does it mean if an attribute has the value NULL?

A null value represents data that’s unspecified, unknown, or not applicable. It’s important not to confuse null with zero, or a blank space character. Null means literally nothing at all or no data.

What do NULL values mean when using the join multiple tool?

When you’re using the join tool, data only joins up if it’s equal. This means, that where you have a NULL, Alteryx would only be able to join it up with another NULL in the other table.
 

What happens if we have NULL values in grouping attributes?

If a grouping column contains null values, all null values are considered equal, and they are put into a single group.