lib/database/schemaGenerators.js
function (name, type, opts) {
            opts = opts || {};
            this.operations.push(merge({op:"setColumnType", name:name, type:type}, opts));
        }
function (name, type, opts) {
            opts = opts || {};
            this.operations.push(merge({op:"setColumnType", name:name, type:type}, opts));
        }
function ( name , type , opts ) { opts = opts || { } ; this . operations . push ( merge ( { op : "setColumnType" , name : name , type : type } , opts ) ) ; }
Modify a column's type in the DDL for the table.

@example
DB.alterTable("artist", function(){
this.setColumnType("artist_name", 'char(10)');
//=> ALTER COLUMN artist_name TYPE char(10)
});
Modify a column s type in the DDL for the table .