Key Changes in the Syntax

To extend ABAP SQL, two fundamental adjustments to the standard were necessary.

Commas in the Field List

Now, every column name must be followed by a comma.
Previously, this wasn’t required since expressions weren’t allowed in the field list —
so it was always clear what was a field.
Now we need a delimiter:

Escaping Host Variables with @

Until now, host variables (= ABAP variables) could only appear in certain predefined places,
so escaping wasn’t needed.
Now they can be used almost anywhere in expressions.

INTO / APPENDING Comes at the End

To allow UNION operations in ABAP SQL,
the INTO clause must appear last — after all individual SELECT statements.

Expressions in the Field List

The field list can now contain more than just columns from source tables.
The following expressions are also allowed:

• SQL functions
• Operator expressions such as calculations or concatenations using +, -, *, /, and &&
• Type conversions using CAST
• CASE expressions
• Window functions

SQL Functions for Strings

SQL Functions for Date and Time

Many SQL functions require an error handling behavior (<on_error>).
Possible values are defined in the respective global ABAP classes as enumerations, e.g. class SQL_TSTMPL_TO_UTCL:

• SQL_TSTMPL_TO_UTCL=>C_ON_ERROR-FAIL
• SQL_TSTMPL_TO_UTCL=>C_ON_ERROR-SET_TO_NULL
• SQL_TSTMPL_TO_UTCL=>C_ON_ERROR-SET_TO_INITIAL

If the source value in conversions is initial, the behavior can also be specified:

• SQL_TSTMPL_FROM_UTCL=>C_ON_INITIAL-FAIL
• SQL_TSTMPL_FROM_UTCL=>C_ON_INITIAL-SET_TO_NULL
• SQL_TSTMPL_FROM_UTCL=>C_ON_INITIAL-SET_TO_INITIAL

Operator Expressions

Calculations

Calculations using +, -, and * work as usual.
Division with / is allowed only for float data types.
Instead, use the SQL function DIVISION(numerator, denominator, #decimals).

String Concatenation

Strings can be concatenated using the && operator.

CASE Expressions – Simple

The CASE expression returns exactly one value:

CASE value
      WHEN compare_value1 THEN result_value1
      WHEN compare_value2 THEN result_value2
      ...
      ELSE alternative_value
END

Every occurrence of “value” can be any valid expression.

Associations

select from I_SalesDocument
   FIELDS
     SalesDocument,
     _item[ (1) inner where SalesDocumentItem = '000010' ]-SalesDocumentItem,
     _item[ (1) inner where SalesDocumentItem = '000010' ]-Material,
     _item[ (1) inner where SalesDocumentItem = '000010' ]-_Material-MaterialBaseUnit,
     _item[ (1) inner where SalesDocumentItem = '000010' ]-_material_Text[ (1) inner where Language = @sy-langu ]-MaterialName
     into table @data(result).

out->write( result ).
ENDMETHOD.

Structure of Window Functions – PARTITION

SELECT location,
       ldate,
       value,
       SUM( value ) OVER( PARTITION BY location )
                                      AS lsum
FROM zbc_wf
ORDER BY location,
         ldate

Structure of Window Functions – ROWS

SELECT location,
       ldate,
       value,
       SUM( value ) OVER( PARTITION BY location
                             ORDER BY ldate
                         ROWS BETWEEN 1 PRECEDING
                                  AND 1 FOLLOWING )
                                          AS lsum
FROM zbc_wf
ORDER BY location,
         ldate
INTO TABLE @DATA(result).

Window Functions – Accessing Other Rows

With LEAD() and LAG() you can access data from rows before or after the current one —
for example, to calculate differences from the previous row.

Syntax

LAG(<expression>[,<offset>])
LEAD(<expression>[,<offset>])

Common Table Expressions (CTE) with WITH (since 7.51)

The idea of CTEs is to reduce nested SELECT statements
by defining table expressions beforehand.

WITH +<CTE_X> AS (SELECT ... FROM <Table_A>)

SELECT ...
  FROM <Table_B>
  INNER JOIN +<CTE_X>
  INTO TABLE ...

This is conceptually similar to defining a VIEW or a table variable in SQLScript.

The major advantage compared to using an internal table in a SELECT is that
the entire query is processed by the HANA database — usually much faster.

JOIN with Internal Tables

SAP Documentation

Clean Code Recommendations

• Clean formatting with indentation and line breaks:

CASE WHEN due_date > @sy-datum
        THEN division( 10,
                       abs( days_between( @sy-datum,
                                          due_date ) ),
                       4 ) * priority
        ELSE priority END
                            AS weighted_priority,