Add discoverExportedForeignKeys

lib/datasource.js

@@ -426,6 +426,41 @@ DataSource.prototype.discoverForeignKeysSync= function(owner, table) {
     return null;
 }
 
+/**
+ * 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.
+ *
+ * fkOwner String => foreign key table schema (may be null)
+ * fkName String => foreign key name (may be null)
+ * fkTableName String => foreign key table name
+ * fkColumnName String => foreign key column name
+ * keySeq short => sequence number within a foreign key( a value of 1 represents the first column of the foreign key, a value of 2 would represent the second column within the foreign key).
+ * pkOwner String => primary key table schema being imported (may be null)
+ * pkName String => primary key name (may be null)
+ * pkTableName String => primary key table name being imported
+ * pkColumnName String => primary key column name being imported
+ *
+ * @param owner
+ * @param table
+ * @param cb
+ */
+DataSource.prototype.discoverExportedForeignKeys= function(owner, table, cb) {
+    this.freeze();
+    if (this.adapter.discoverExportedForeignKeys) {
+        this.adapter.discoverExportedForeignKeys(owner, table, cb);
+    } else if (cb) {
+        cb();
+    }
+}
+
+DataSource.prototype.discoverExportedForeignKeysSync= function(owner, table) {
+    this.freeze();
+    if (this.adapter.discoverExportedForeignKeysSync) {
+        return this.adapter.discoverExportedForeignKeysSync(owner, table);
+    }
+    return null;
+}
+
 function capitalize(str) {
     if (!str) {
         return str;