let say we have a table with following records...
DatabaseSchemaTable : SchemaId, SchemaName
TablesTable: TableName, TableColumns, SchemaId
// then some more tables to define how tablestable's record to have relationships to each other
SchemaTable
1 CustomerPortal ERD
2 ShipyardSystem Portal ERD
TablesTable
SchemaId : 1, TableName: User, Columns:....