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Description

This error occurs in SAP S/4HANA when an expression on the left-hand side of an SQLScript assignment statement is not a valid target for modification. It indicates an attempt to assign a value to something that cannot accept an assignment, such as a constant, literal, or an invalid expression.

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Error Message

ERR_SQLSCRIPT_LHS_CANNOT_ASSIGNED: Expression is inappropriate as the left hand side of an assignment statement

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Known Causes

3 known causes

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Assigning to a Constant or Literal

Attempting to assign a new value to a fixed constant or a literal value, which cannot be modified in SQLScript.

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Invalid Expression on LHS

The left-hand side of the assignment is a complex expression or function call, not a simple variable or parameter.

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Read-Only Variable or Parameter

Trying to modify a variable or parameter that is explicitly or implicitly declared as read-only within its scope.

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Solutions

3 solutions available

1. Correcting Invalid Assignment in SQLScript medium

Ensures the left-hand side of an assignment in SQLScript is a valid target.

1

Identify the SQLScript code that is causing the error. This typically occurs within stored procedures, functions, or CDS views that utilize SQLScript.

Look for statements like `expression = ...` where 'expression' is not a valid variable, parameter, or column that can be assigned a value.

2

Analyze the 'expression' on the left-hand side of the assignment. It must be a modifiable element.

Common valid LHS targets include: declared variables (e.g., `lv_counter`), input parameters (if the script allows modification, though rare for input parameters), or table columns in certain contexts (e.g., within an UPDATE statement, but not a direct assignment in a procedure body).

3

Modify the SQLScript to assign a value to a valid target. If you intended to calculate a value, assign it to a declared variable.

Example of incorrect assignment:
sql
RETURN (SELECT COUNT(*) FROM my_table) = my_variable;

Example of correct assignment:
sql
my_variable = (SELECT COUNT(*) FROM my_table);
RETURN my_variable;

4

If the expression is a literal, a function call that returns a value but is not a variable, or a subquery that is not being assigned to a variable, it needs to be adjusted.

Ensure that the right-hand side of the assignment is being evaluated and its result is being stored in a valid variable or parameter on the left.

2. Reviewing CDS View Associations and Assignments medium

Validates assignments within CDS views, especially those involving associations.

1

Examine the CDS view definition where the error is occurring. Pay close attention to any `association` definitions and how fields are being projected or calculated.

Look for scenarios where you might be trying to assign a complex expression or a value from an association directly to a field that is not intended for direct assignment or is a literal/view name.

2

Ensure that any calculated fields or projected values are correctly assigned to the target field within the CDS view's select list.

If an association is used, verify that you are projecting fields from the associated entity correctly, not attempting to assign the association itself or a non-assignable expression to a field.

3

For example, if you are trying to assign a count from an association, ensure it's done via a subquery assignment to a calculated field.

Incorrect:
cds
@AbapCatalog.sqlViewName: 'MYCDSVIEW'
@AbapCatalog.compiler.compareFilter: true
@AccessControl.authorizationCheck: #CHECK
@VDM.viewType: #BASIC
define view MyCDSView as select from MyEntity as Entity
{
  key Entity.ID,
  Entity.Name,
  (select count(*) from Entity.MyAssociation) = Entity.AssociationCount // Incorrect assignment
}

4

Correct the CDS view definition to assign the calculated value to a field properly.

Correct:
cds
@AbapCatalog.sqlViewName: 'MYCDSVIEW'
@AbapCatalog.compiler.compareFilter: true
@AccessControl.authorizationCheck: #CHECK
@VDM.viewType: #BASIC
define view MyCDSView as select from MyEntity as Entity
{
  key Entity.ID,
  Entity.Name,
  @Semantics.quantity.unitOfMeasure: true
  @Aggregation: #SUM
  (select count(*) from Entity.MyAssociation) as AssociationCount // Correct assignment to a projected field
}

3. Debugging Stored Procedures and Functions advanced

Systematically debug stored procedures or functions to pinpoint the invalid assignment.

1

Use the ABAP Development Tools (ADT) for Eclipse to debug the stored procedure or function.

Right-click on the stored procedure/function in ADT and select 'Debug As' -> 'ABAP Application'.

2

Set breakpoints at the beginning of the procedure/function and step through the code line by line.

Execute the debug session and observe the execution flow.

3

When the debugger stops at or just before the error occurs, inspect the values of variables and expressions involved in assignment statements.

Focus on any line where a value is being assigned using the `=` operator.

4

Identify the specific expression on the left-hand side that is not a valid target for assignment. This might be a literal, a constant, a function call that doesn't return a variable, or an incorrect reference.

Once identified, correct the SQLScript logic to assign to a declared variable, a parameter, or a valid column as intended.

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Related Errors

5 related errors

SAP S/4HANA Error 1290: Invalid SQLScript Assignment LHS