Making sure that keys cannot be duplicated for primary keys, this wouldn't have any function.

packages/server/src/integrations/mysql.ts

@@ -163,7 +163,7 @@ module MySQLModule {
         )
         for (let column of descResp) {
           const columnName = column.Field
-          if (column.Key === "PRI") {
+          if (column.Key === "PRI" && primaryKeys.indexOf(column.Key) === -1) {
             primaryKeys.push(columnName)
           }
           const constraints = {

packages/server/src/integrations/postgres.ts

@@ -147,7 +147,11 @@ module PostgresModule {
           if (!tableKeys[tableName]) {
             tableKeys[tableName] = []
           }
-          tableKeys[tableName].push(table.column_name || table.primary_key)
+          const key = table.column_name || table.primary_key
+          // only add the unique keys
+          if (key && tableKeys[tableName].indexOf(key) === -1) {
+            tableKeys[tableName].push(key)
+          }
         }
       } catch (err) {
         tableKeys = {}