Function generateDBMLFromDiagram

src/lib/dbml/dbml-export/dbml-export.ts:1364–1606

(diagram: Diagram)

}

export function generateDBMLFromDiagram(diagram: Diagram): DBMLExportResult {
    // Filter out fields with empty names
    const sanitizedTables =
        diagram.tables?.map((table) => {
            const validFields = table.fields.filter(
                (field) => field.name !== ''
            );
            return {
                ...table,
                fields: validFields,
            };
        }) ?? [];

    // Filter out empty tables and duplicates in a single pass for performance
    const seenTableIdentifiers = new Set<string>();
    const tablesWithFields = sanitizedTables.filter((table) => {
        // Skip tables with no fields (empty tables cause DBML export to fail)
        if (table.fields.length === 0) {
            return false;
        }

        // Create a unique identifier combining schema and table name
        const tableIdentifier = table.schema
            ? `${table.schema}.${table.name}`
            : table.name;

        // Skip duplicate tables
        if (seenTableIdentifiers.has(tableIdentifier)) {
            return false;
        }
        seenTableIdentifiers.add(tableIdentifier);
        return true; // Keep unique, non-empty table
    });

    // Create the base filtered diagram structure
    const filteredDiagram: Diagram = {
        ...diagram,
        tables: tablesWithFields,
        relationships:
            diagram.relationships?.filter((rel) => {
                const sourceTable = tablesWithFields.find(
                    (t) => t.id === rel.sourceTableId
                );
                const targetTable = tablesWithFields.find(
                    (t) => t.id === rel.targetTableId
                );
                const sourceFieldExists = sourceTable?.fields.some(
                    (f) => f.id === rel.sourceFieldId
                );
                const targetFieldExists = targetTable?.fields.some(
                    (f) => f.id === rel.targetFieldId
                );

                return (
                    sourceTable &&
                    targetTable &&
                    sourceFieldExists &&
                    targetFieldExists