Fix discovery of exported keys

example/app.js

@@ -1,6 +1,3 @@
-var config = require('rc')('loopback');
-config = (config.test && config.test.mysql) || {};
-
 var DataSource = require('loopback-datasource-juggler').DataSource;
 
 var config = require('rc')('loopback', {dev: {mysql: {}}}).dev.mysql;
@@ -23,17 +20,17 @@ function show(err, models) {
 
 ds.discoverModelDefinitions({views: true, limit: 20}, show);
 
-ds.discoverModelProperties('User', show);
+ds.discoverModelProperties('customer', show);
 
-ds.discoverModelProperties('Post', {owner: 'test'}, show);
+ds.discoverModelProperties('location', {owner: 'strongloop'}, show);
 
-ds.discoverPrimaryKeys('User', show);
-// ds.discoverForeignKeys('User',  show);
+ds.discoverPrimaryKeys('customer', show);
+ds.discoverForeignKeys('inventory',  show);
 
-// ds.discoverExportedForeignKeys('User',  show);
+ds.discoverExportedForeignKeys('location',  show);
 
 
-ds.discoverAndBuildModels('User', {owner: 'test', visited: {}, associations: true}, function (err, models) {
+ds.discoverAndBuildModels('weapon', {owner: 'strongloop', visited: {}, associations: true}, function (err, models) {
 
     for (var m in models) {
         models[m].all(show);

lib/discovery.js

@@ -344,30 +344,22 @@ function mixinDiscovery(MySQL) {
      * @returns {string}
      */
     function queryExportedForeignKeys(owner, table) {
-        var sql = 'SELECT a.constraint_name AS "fkName", a.owner AS "fkOwner", a.table_name AS "fkTableName",'
-            + ' a.column_name AS "fkColumnName", a.position AS "keySeq",'
-            + ' jcol.constraint_name AS "pkName", jcol.owner AS "pkOwner",'
-            + ' jcol.table_name AS "pkTableName", jcol.column_name AS "pkColumnName"'
+        var sql = 'SELECT a.constraint_name AS "fkName", a.table_schema AS "fkOwner", a.table_name AS "fkTableName",'
+            + ' a.column_name AS "fkColumnName", a.ordinal_position AS "keySeq",'
+            + ' NULL AS "pkName", a.referenced_table_schema AS "pkOwner",'
+            + ' a.referenced_table_name AS "pkTableName", a.referenced_column_name AS "pkColumnName"'
             + ' FROM'
-            + ' (SELECT'
-            + ' uc1.table_name, uc1.constraint_name, uc1.r_constraint_name, col.column_name, col.position, col.owner'
-            + ' FROM'
-            + ' information_schema.key_column_usage'
-            + ' WHERE'
-            + ' uc.constraint_type=\'P\' and uc1.r_constraint_name = uc.constraint_name and uc1.constraint_type = \'R\''
-            + ' and uc1.constraint_name=col.constraint_name';
+            + ' information_schema.key_column_usage a'
+            + ' WHERE a.position_in_unique_constraint IS NOT NULL';
         if (owner) {
-            sql += ' and col.owner=\'' + owner + '\'';
+            sql += ' and a.referenced_table_schema=\'' + owner + '\'';
         }
         if (table) {
-            sql += ' and uc.table_Name=\'' + table + '\'';
+            sql += ' and a.referenced_table_name=\'' + table + '\'';
         }
-        sql += ' ) a'
-            + ' INNER JOIN'
-            + ' USER_CONS_COLUMNS jcol'
-            + ' ON'
-            + ' a.r_constraint_name=jcol.constraint_name'
-            + ' order by a.owner, a.table_name, a.position';
+        sql += ' order by a.table_schema, a.table_name, a.ordinal_position';
+
+        console.log(sql);
 
         return sql;
     }