Open SQL - Null Values - ABAP Keyword Documentation

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Open SQL - Null Values

A null value is an initial value of an empty column in the row of a database table. Null values do not correspond to any content of data objects in ABAP.

In Open SQL, null values can handled using the condition IS NULL and the function coalesce. Modifying Open SQL statements generally do not create null values, provided that a view is not being edited that does not comprise all columns of a database table. However, depending on the database system, empty strings can also be displayed as null values. Null values can still arise in database tables if the new columns are appended to filled tables.

In reads using the Open SQL statement SELECT, null values can be produced by aggregate functions, SQL expressions, and in outer joins. When passed to data objects, these values are transformed to type-friendly initial values, but are handled as standalone values in the additions GROUP BY and ORDER BY. Null values are also transformed to initial values in SAP buffering.

Notes

In Native SQL, null values passed to ABAP objects are also transformed to their type-friendly initial values.

In ABAP Dictionary, a flag for initial values can be set when inserting new columns in existing database tables to preserve the type-friendly initial value instead of the null value.