README.md

Freemarker Dynamic QL(SQL/JPQL/HQL/...) Builder

Do you need to build native SQL dynamically in Java application? But are you worried about how to bind query parameters? Look at the following example.

When you have this file users/select.ql.ftl

SELECT *
FROM somewhere
<@ql.where>
    <#if user.name?has_content>
    name = ${param(user.name)}
    </#if>
    <#if user.birthyear gt 0>
    AND birthyear = ${param(user.birthyear)}
    </#if>
    <#if user.employeeType??>
    AND employeeType = ${param(user.employeeType, 'enumToName')}
    </#if>
    <#list userIds!>
    AND userId IN (<#items as userId>${param(userId)}<#sep>,</#sep></#items>)
    </#list>
</@ql.where>

ORDER BY userId
LIMIT 10

Run this template with the following java code

FreemarkerDynamicQlBuilder dynamicQlBuilder = ....;

User user = new User();
user.setName(""); // empty on purpose
user.setBirthyear(2015);
user.setEmployeeType(EmployeeType.FULLTIME);

Map<String,Object> dataModel = new HashMap<String,Object>();
dataModel.put("user", user);
dataModel.put("userIds", new int[]{100, 200, 300});

DynamicQuery dynamicQuery = dynamicQlBuilder.buildQuery("users/select", dataModel);

Then you will get DynamicQuery object with the following properties

dynamicQuery.getQueryString() 
==> String
"SELECT *
FROM somewhere
WHERE birthyear = ?
    AND employeeType = ?
    AND userId IN (?,?,?)
ORDER BY userId
LIMIT 10"

dynamicQuery.getParameters()
==> List<Object> : [2015, FULLTIME, 100, 200, 300] 

dynamicQuery.getQueryParameterArray()
==> Object[] : [2015, FULLTIME, 100, 200, 300] 

Getting Started

• Freemarker Dynamic QL Builder 시작하기 - 한국어
• Getting Started Freemarker Dynamic QL Builder - English

Requirements

• Java 6 or later
• This library depends on only freemarker 2.3.23+ and slf4j.