Loopback Model Creation

The project is generated using LoopBack and modified by savsharma2 to create models with belongsTo that is One To One and hasMany which is One To Many relationships.

Installation

$ npm install

Change in loopback discovery api

Problem statement can be viewed here (http://stackoverflow.com/questions/37408747/strongloop-database-discovery-api-for-sql-server-giving-same-table-name-for-prim).

file :- node_modules/loopback-connector-mssql\lib\discovery.js

/*!
 * Retrieves a description of the foreign key columns that reference the given table's primary key columns (the foreign keys exported by a table).
 * They are ordered by fkTableOwner, fkTableName, and keySeq.
 * @param owner
 * @param table
 * @returns {string}
 */
function queryExportedForeignKeys(owner, table) {
  var sql = `SELECT
  fkOwner = sch.name ,fkName = obj.name,
  fkTableName =  tab1.name ,
  fkColumnName = col1.name,
  PK_Table =  tab2.name,
  PK_Column = col2.name
  FROM sys.foreign_key_columns fkc
  INNER JOIN sys.objects obj
      ON obj.object_id = fkc.constraint_object_id
    INNER JOIN sys.tables tab1
      ON tab1.object_id = fkc.parent_object_id
    INNER JOIN sys.schemas sch
      ON tab1.schema_id = sch.schema_id
    INNER JOIN sys.columns col1
      ON col1.column_id = parent_column_id AND col1.object_id = tab1.object_id
    INNER JOIN sys.tables tab2
      ON tab2.object_id = fkc.referenced_object_id
    INNER JOIN sys.columns col2
      ON col2.column_id = referenced_column_id AND col2.object_id = tab2.object_id`;

  if (table) {
    sql += ' and tab2.name=\'' + table + '\'';
  }

  return sql;
}

/*!
 * Build the sql statement for querying foreign keys of a given table
 * @param owner
 * @param table
 * @returns {string}
 */
function queryForeignKeys(owner, table) {
  var sql = `SELECT  
     fkOwner = FK.table_schema ,
     fkName = FK.constraint_name,
     fkTableName = FK.TABLE_NAME,
     fkColumnName = CU.COLUMN_NAME,
     keySeq = CU.ordinal_position,
     PK_Table = PK.TABLE_NAME,
     PK_Column = PT.COLUMN_NAME
     FROM
     INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS C
     INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS FK
        ON C.CONSTRAINT_NAME = FK.CONSTRAINT_NAME
     INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS PK
        ON C.UNIQUE_CONSTRAINT_NAME = PK.CONSTRAINT_NAME
     INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE CU
        ON C.CONSTRAINT_NAME = CU.CONSTRAINT_NAME
     INNER JOIN (
          SELECT
              i1.TABLE_NAME,
              i2.COLUMN_NAME
          FROM
              INFORMATION_SCHEMA.TABLE_CONSTRAINTS i1
          INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE i2
              ON i1.CONSTRAINT_NAME = i2.CONSTRAINT_NAME
          WHERE
              i1.CONSTRAINT_TYPE = 'PRIMARY KEY'
         ) PT
     ON PT.TABLE_NAME = PK.TABLE_NAME`;

  if (table) {
    sql += ' AND  FK.TABLE_NAME =\'' + table + '\'';
  }
  return sql;
}

Running Project

run

node .

and you are good to go. :+1: