sql-engine

Simple sql template engine, very small, no need to introduce external packages (you can change a few lines of code without introducing any external packages).

Dependency

Requires JDK1.8+ support.
Maven

<dependency>
    <groupId>com.tollge</groupId>
    <artifactId>sql-engine</artifactId>
    <version>0.1.0</version>
</dependency>

Gradle

compile 'com.tollge:sql-engine:0.1.0'

sql template

select *
from tab
where a = #a#
?if b='bb' ??
and b = #b#
?else
and b != #b#
if?

java code

Map<String, Object> params = new HashMap<>();
params.put("a", "a");
params.put("b", "bbb");
SqlTemplate.generateSQL("test.testIf", params)

output:

sql: select * from tab where a = ? and b != ?
params: [a, bbb]

grammar

IF

The conditional rules of if will be discussed later

?if a==1 ??
  mix
  if?

IF_ELSE

?if a==1 ??
  mix
  ?else
  mix
  if?

FOR

?for a?as ??
  mix
  for

FOR_WITH

b is string

?for a?as ?with b ??
  mix
  for?

SUB

sub template

?sub test.testSub sub?

IF condition

IF Conditional engine is open sourcejexparser
it contains 3 classes, just copy into the jar.

Currently supported:

>  <  =  >=  <=  
+  -  *  /  
or  and  not  
'  ( )  ?  0~9 . 
equals  equalsIgnoreCase  contains  containsIgnoreCase  
startWith  startWithIgnoreCase  endWith  endWithIgnoreCase

Added a keyword based on it: isNotNull

User Guide

sql template folder: mapper
sql template file type: .md (yeah, it is markdown)
Template file composition:

## testIf      ->   key of sql
> Comment:test If   -> Comment
```sql         -> sql content

```sub         -> sub template,Can only be referenced by sql template

When the SqlTemplate class is initialized, all sql templates are loaded and saved as xxx.testIf, xxx is the file name, and testIf is the sql key. You need to call:

SqlTemplate.generateSQL("xxx.testIf", params)