# Function: convertToLegacyJsonMapping()

convertToLegacyJsonMapping(input): LegacyJsonMapping

Defined in: packages/core/src/transformers/EnhancedJsonMapping.ts:210

Converts any unified JSON mapping format to legacy JsonMapping format.

This universal converter handles Enhanced, Unified, and Legacy formats, providing a single interface for converting complex mapping configurations to the simple format expected by PostgresJsonQueryBuilder.

Supported Input Formats:

• Enhanced: With metadata, type protection, and advanced column configs
• Unified: Standard format with rootName and rootEntity
• Legacy: Already compatible format (returned as-is)

Features:

• Automatic format detection
• Column configuration simplification
• Nested entity handling
• Type protection extraction

Parameters

input

any

JSON mapping in any supported format

Returns

LegacyJsonMapping

Legacy JsonMapping compatible with PostgresJsonQueryBuilder

Throws

When input is null, undefined, or malformed

Example

// Enhanced format input
const enhanced = {
  rootName: "User",
  rootEntity: {
    columns: {
      id: { column: "u.user_id", type: "number" },
      name: { column: "u.user_name", type: "string" }
    }
  },
  metadata: { version: "2.0" }
};

const legacy = convertToLegacyJsonMapping(enhanced);
// Result: Compatible with PostgresJsonQueryBuilder

See

• convertColumnsToLegacy For column-specific conversion
• extractTypeProtection For type safety features