Main goal of SQLMaster is to have only one template - both for SQL development and template engine.
Template is plain SQL and markup placed inside javadoc comments - /** and */
There are two kind of syntax constructs: parameters and embedded text.
Typical workflow for SQL Master:
- load template
- assign parameter values
- enable embedded text
- render template
To load template use Engine:
String templateText = ...;
Template t = Engine.load(templateText);Template provides API to work with template.
To generate template simple call process method of Template
Parameter is a markup element for parameter values substitution. Here it is typical usage:
select * from client where name = /** string client(*/'John'/**)*/Each parameter have name and type. In example above name is "client" and type is "string". Name is used to identify parameter in template. Type is SQL type used to control type values at runtime.
To assign parameter value use assignValue method of Template:
template.assignValue("client", "Mike")You can place multiple parameters with same name in template. When you assign value for such parameters all occurences will be rendered with given value.
If parameter should be rendered and no value assigned to it exception occurs.
Parameters can contains only plaintext inside of them.
Parameter may contains plaintext inside it to provide 'default values'. These values used to simplify work in SQL editor and will be removed in time of template rendering. These two templates are equivalent:
select * from client where name = /** string client(*/'John'/**)*/select * from client where name = /** string client()*/Embedded text is used to insert some predefined text in you template. Most time it used to add some optional joins or conditions. Here it is syntax example:
selet *
from client c
/** fullInfo{*/inner join client_info ci on ci.client_id = c.id /**}*/By default embedded text is not rendered. There are two ways to render embedded text:
- explicit call of
enablemethod - cascade enable (read bellow)
Embedded text can contains another embedded text and parameters.
Most case when you need embedded text is options where clause or optional joins. Both of them should be enabled only when you set value of parameter. Here it is typical usage:
select * from client c
/** additionalInfo{*/ inner join client_info ci on ci.client_id = c.id /**}*/
where c.name = /** string name(*/'john'/**)*/
/** additionalInfo{*/ and ci.address = /** string address(*/'Novosibirsk'/**)}*/Here you can see two parameters - name and address. address is placed inside embedded text