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https://github.com/joutvhu/spring-dynamic-velocity
Velocity dynamic query template provider.
https://github.com/joutvhu/spring-dynamic-velocity
dynamic-query query-template spring velocity
Last synced: 25 days ago
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Velocity dynamic query template provider.
- Host: GitHub
- URL: https://github.com/joutvhu/spring-dynamic-velocity
- Owner: joutvhu
- License: mit
- Created: 2022-12-22T19:16:56.000Z (about 2 years ago)
- Default Branch: main
- Last Pushed: 2023-07-28T07:02:38.000Z (over 1 year ago)
- Last Synced: 2024-11-13T12:11:47.260Z (3 months ago)
- Topics: dynamic-query, query-template, spring, velocity
- Language: Java
- Homepage:
- Size: 148 KB
- Stars: 1
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md
Awesome Lists containing this project
README
# Spring Dynamic Velocity
A [Dynamic Query Template Provider](https://github.com/joutvhu/spring-dynamic-commons#dynamic-query-template-provider) base on [Apache Velocity](https://velocity.apache.org) template engine.
You can refer to [Velocity Document](https://velocity.apache.org/engine/devel/user-guide.html) to know more about rules.
## Using
You need to configure a VelocityQueryTemplateProvider bean to use this template provider.
```java
@Bean
public DynamicQueryTemplateProvider dynamicQueryTemplateProvider() {
VelocityQueryTemplateProvider provider = new VelocityQueryTemplateProvider();
provider.setEncoding("UTF-8");
provider.setTemplateLocation("classpath:/query");
provider.setSuffix(".dsql");
return provider;
}
```
The VelocityQueryTemplateProvider has the following parameters:
- `setTemplateLocation`: in case you do not specify the query template on the `@DynamicQuery` annotation, the provider will find it from external template files. The TemplateLocation Is location you put the external template files, default is `classpath:/query`
- `setSuffix`: is the suffix of the external template files, default is `.dsql`. If you don't want the provider to load external templates then set this value to `null`.
- `setEncoding`: is the encoding of templates, default is `UTF-8`
- `setConfiguration`: is a VelocityTemplateConfiguration, used to customize Velocity configuration.
Each template in external template file will start with a template name definition line. The template name definition line must be start with two dash characters (`--`).
## Directives
### Where Directive
`#where` directive knows to only insert `WHERE` if there is any content returned by the containing tags. Furthermore, if that content begins or ends with `AND` or `OR`, it knows to strip it off.
```sql
select t from User t
#where
#if($firstName != $null)
and t.firstName = :firstName
#end
#if($lastName != $null)
and t.lastName = :lastName
#end
#end
```
### Set Directive
`#set` directive is like the `#where` directive, it removes the commas if it appears at the begins or ends of the content. Also, it will insert `SET` if the content is not empty.
```sql
update User t
#set
#if($firstName != $null)
t.firstName = :firstName,
#end
#if($lastName != $null)
t.lastName = :lastName,
#end
#end
where t.userId = :userId
```
Note to avoid confusion with [the #set directive used for setting the value of a reference](https://velocity.apache.org/engine/devel/user-guide.html#set).
This `#set` directive is a block of `#set` _(without parameters)_ and `#end`.
### Trim Directive
`#trim` directive has four parameters: `prefix`, `prefixOverrides`, `suffix`, `suffixOverrides`.
- `prefix` _(first parameter)_ is the string value that will be inserted at the start of the content if it is not empty, value type is string.
- `prefixOverrides` _(second parameter)_ are values that will be removed if they are at the start of a content, value type is list of strings.
- `suffix` _(third parameter)_ is the string value that will be inserted at the end of the content if it is not empty, value type is string.
- `suffixOverrides` _(fourth parameter)_ are values that will be removed if they are at the end of a content, value type is list of strings.
```sql
#trim("where (", ["and ", "or "], ")", [" and", " or"])
#if($productName != $null)
t.productName = :productName or
#end
#if($category != $null)
t.category = :category or
#end
#end
```