sql-cast-suggestion

Rule Details

With compiler v2, appending a type declaration to a column expression in a view's query doesn't generate a cast in SQL anymore, as that created conflicts with various database-specific behaviors. This rule ensures that such casts are added explicitly by suggesting possible missing SQL casts.

Examples

✅   Correct example

In the following example, the entity ListOfBooks contains explicit casts for elements name2 and name3, so the rule will not be triggered for these elements:

db/schema.cds

namespace sap.capire.bookshop;

entity Books {
  key ID : Integer;
  @mandatory title  : localized String(111);
  @mandatory name   : localized String(111);
}

entity ListOfBooks as SELECT from Books {
  *, ID,
  title || name as name1 : String,
  cast (title || name as String) as name2,
  cast (title || name as String) as name3 : String,
};

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❌   Incorrect example

In the next example, the rule will be triggered for elements name1 and name2 because they require explicit casts:

db/schema.cds

namespace sap.capire.bookshop;

entity Books {
  key ID : Integer;
  @mandatory title  : localized String(111);
  @mandatory name   : localized String(111);
}

// Potential issue - Missing SQL cast for column expression?
// Potential issue - Missing SQL cast for column expression?
entity ListOfBooks as ( 
  SELECT from Books {
    title || name as name1 : String,
  }
) UNION (
  SELECT from Books {
    title || name as name2 : String,
  }
);

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Version

This rule was introduced in @sap/eslint-plugin-cds 1.0.8.